31 October 2011

Electrons of time

It’s 5 pm on Halloween; dusk; the end of October, the eve of November and all hallows. These endings and beginnings seem only infinitesimally small marks on a continuum, rather than events with a real scope. The electrons of time. Comprehensible yet indescribable (and how apt that the last letters of that last word are so close to babble).

The donut is blown, ideas have been propagated, knowledge transferred, thoughts translated into other forms. And yet for me this process continues, with knowledge still distilling and being regurgitated in altered shapes. I continue to make things that are expressions of the time spent and information learned whilst I have woven the course of this process. Art. But this blog will end here. It is transmogrifying into another, a continuum of the work under another title. ‘Virtually resident’, the words that directly report my time as Leverhulme artist in residence at the University of Surrey, ends today. And do I have a final comment on which to close? I would caution my fellow makers against Residences that are geographically removed from their residences, it is a challenge. And what of silicon photonics? The process of science marches on. Today the population of the world purportedly reached seven billion; there is an ever increasing need for efficiency in our utilisation of resources; there is much for us to do to ease the existence of humanity. There is so much potential in seven billion people, so much that we have yet to do and discover. 

For me, part of my immediate future endeavour (my beatific vision?) is taking the form of words and images relating to science, silicon photonics, art, as a book, of which you can read more here. And so my final word here in conclusion (and which is, after all, merely the marking of a minutely transient moment)? I think it will simply be inconclusion.

12 October 2011

Blowing the dough (part 1)

I had wanted to write yesterday due to the binary beauty of the date, but the day was taken up with other Art matters, and the opportunity did not arise. More of that later, for now a report on the remarkably readily possible undertaking of the impossible.

A year ago I heard of a thing called a ring resonator. This object was at that time completely new to me, and my instantaneous, unstoppable response to hearing those words was an image of a luminous, diaphanous structure, floating in the nothingness of my mind. A glass circular form, indescribably light and fragile, imperceptibly pulsing with the energies of the universe, emitting an infinite range of coloured light from its integrally transparent curved clarity. A glass doughnut. 

And over the subsequent times that I have spent residing with the silicon photonics group this vitreous image has repeatedly reappeared, silently animate as it has been mulled in my mind. I had sought to make one, to have one made, but with no success, not least because of my stubborn demand that it must be blown rather than cast glass (to me there is a dynamism resulting from the trapped vitality of the former that is less evident in the latter). It was not possible. In a final effort to construct this wonder I set out on an impossible mission last week, blowing the last of the grant, and spent it at a glass studio on an exploration of the potential of the doughnut's formation, questioning the edges of its possible construction – is it really impossible?

And so it seems that the answer is no. It was made at first attempt through a combination of Kim’s expertise and a slightly brutish attacking of the glowing molten blob. True to say that the small leaden lump of chunky glass with rough edges that is the semblance of a glass doughnut does not exactly mirror the one in my mind, but technically it is exactly the thing I wish to construct. How easy (if a little diminutive) the impossible can sometimes be. The second go was neater but still small, and the third (again small) is as yet unseen by me as it had to be left in the annealing oven to prove when I departed. Now is the time to get excited about the fourth, which is to be constructed next week, and is to be as large as possible. Theoretically the limiting factor of this possibility is the size of the glory hole (the boxed blow torch that is used to reheat glass to enable continued working on it), so there is a technical finity to this thing that is somewhat more expansive in my head. But I am heartened that in the last week of my official time as artist in residence with the lab I have managed to construct the first thing that I envisaged. Things are looking up.

6 September 2011

What light breaks?

How did Romeo feel as he glimpsed the first shards of light that day as he stumbled into a consciousness of an outer world while encapsulated within Juliet’s? Today a lab meeting, in the boss’s office – up high amidst the wind and rain that is relentlessly affronting the building. A smallish contingent as a result of diverse slowing effects on other members of the group, but I take great pleasure from the interaction, varyingly business like and humorous. I am saddened at the thought that I only have one more month in this place; my time here is mostly gone.

The grey and gloom are pervasive in my mood as I walk around (and only enhanced by stumbling into Jeff Beck singing “Lilac wine” in a cafe as I stop to grab a coffee), and I feel as if my eyes are trying to absorb as much as possible of the quirky visuals that comprise the campus. The assorted travel trophies in the office; a folder entitled ‘Circles of light’; the oversized coffee mug; all the men wearing stripy shirts. These things bear a new weight in the wistfulness of the nostalgia of upcoming departure.

This residency has been a curious creature for me. I am always desolate at having to leave my home, to tear myself away from the peace and otherworldliness of my quiet and secret place. And I keenly feel the transitions into the weird, wider world – the crassness encapsulated in the free paper that has been discarded on my train seat, the towering spindles of teenage girls at the railway station last night, high on their platforms, legs topped by miniscule skirts, and the facile, protracted, fantasies of a Twilight movie that is playing as I arrive at my ever-welcome, ever-welcoming accommodation. And today the transition into this other world, that of the University; externally still slow and quiet, amid the rain, since term has not yet started. Yet behind the silent doors, along the quiet corridors the work beavers on. Here there is an ongoing wave of advancement; the group I am affiliated with are making tiny electronics devices that are at least as good as those made by the giant corporation of Intel; the five unassuming men I met with this morning are creating our future. It is extraordinary, what luxury to be here and share time with them; I am desolate at the thought of leaving again. I speak, yet I say nothing; what of that?

27 August 2011

aging of knowledge

Is there a difference between coming to know something that is known and coming to know something that was formerly unknown? Since all knowledge newly acquired is novel to the acquirer, is there a possibility of discriminating if the thing has previously been thought by others. (Or maybe stated in another way the question is can one detect creativity in oneself (let alone others)?)

What is understanding? Over and again I return to my attempts to envisage what an electron cloud is – why the doped semiconductor is more conductive than the undoped – I can regurgitate a sentence of the bookish teachings of the phenomenon, but I do not feel it. I do not have a sense of how the process actually works.

When I was first resident with Graham’s group I attended some of the lectures by Goran. His teaching leaves space within the lectures for the students to discuss amongst themselves, in order to problem solve and hence develop a deeper understanding of the subject. I was struck by the audio variations of the lectures – periods of low level sound as Goran spoke and showed slides, talked through examples etc, and then periods of vibrant noisy engagement as the students talked about the problem posed, among other less focussed chatterings. To me the energy contained in the audible discourses was the perceptible result of knowledge generation; tonal and volume variations resulting from the degree of insight; the sounds of the evolution of understanding. 

I used to find conversation (and argument) a useful tool for working through ideas, the discussion helping me to understand my view; the externalisation somehow clarifying the subtleties of complex notions. Nowadays I seem to find silent contemplation a more effective mechanism of generating understanding, with non-conscious thought arguably even better than mindful consideration for that purpose. Almost the polar opposite of my earlier method. It’s probably just my age, which is reassuring.

16 August 2011

Stimulating photons

Is it possible that some things are conceivable only in a certain language; that they have no description in the wrong tongue? In trying to understand how lasers work I keep butting up against the fact that they are “triggered” by photons of a suitable energy passing by, and the resulting stimulated emission occurs with the same frequency, plane, energy etc  as the input photon. But why is this so? Why does a passing blip elicit the release of an identical one? Is this phenomenon comprehensible in words? Or pictures? Or is maths the only form in which it can be conceived and communicated?

One explanation, by SM Sze in his afore mentioned “Semiconductor Devices” (1985) states (p. 254):
“When a photon of energy h v12 impinges on an atom while it is in the excited state, the atom can be stimulated to make a transition to the ground state and gives off a photon of energy  h v12, which is in phase with the incident radiation. This process is called stimulated emission. The radiation from stimulated emission is monochromatic because each photon has an energy of precisely h v12 and is coherent because all photons are emitted in phase.”

I do not mean to criticize Mr Sze but although that sounds like an explanation it does not explain to me why stimulated emission occurs, and what it is that is actually occurring. Further reading leads me to Raman scattering and in “Infra-red physics” by Houghton and Smith (1966) am not reassured by the comment with regard to Raman lines (p. 53): “Because the wave-mechanical description of a perturbed system involves all states of the molecule, the intensity of a Raman transition will be determined by a sum over states of products of the transition moments between states. This is too complicated for calculation even in simple cases. ...” 

Time to return to the drawing board, which in this instance is actually a zinc plate since the drawing is an etching. I submit to the frustrations of literal incomprehension, working instead in the realm of visual misrepresentation, and accept, for the moment, that maybe some photons are simply more stimulating than others.

26 July 2011

If something is truly creative then it is invisible as such, since nobody else can recognise it to be so. If you tell everyone what they intrinsically know already, they will think you phenomenally astute and insightful. It’s a matter of perception, which is a strong force to try to break through.

20 July 2011

Elemental homeopathy

Yesterday I set out on a voyage to draw a picture of silicon. I had wanted to draw the silicon atom (and to subsequently work up to the crystal structure) whilst envisaging the positions of the electrons / their orbitals, as I wish to come to a degree of understanding about semiconductors; the freedom, or not, of electrons from the silicon atoms in its crystal lattice appears to be of some import in that regard. 

Semiconductors can conduct a little bit of electricity (more than insulators, less than metals) as a result of loosely bound electrons in their chemical structures that can be liberated by absorption of energy from the environment in the form of heat; with increasing temperature intrinsic semiconductors become more conductive. I had been reading about semiconductor doping, this being a mechanism whereby semiconductor materials (for example silicon) can be altered through the addition of tiny amounts of other chemicals (the dopants) in order to make them more conductive. It’s kind of like elemental homeopathy. The doping materials can either be such as to add electrons to the semiconductor, making it more negative and hence called n-type dopants, or to stick some of the free electrons that exist in the semiconductor more securely into the chemical structure, effectively making it more positive and thus called p-type. P- and n- doping are fundamental processes in silicon photonics where they are used on a precise and minuscule scale to manipulate the passage of current through chips and wafers, etc. I had been fascinated to read that the addition of a single arsenic atom per million atoms of silicon increases the conductivity of the latter by 100,000 times. The arsenic atom has one free electron that it lends to the process (it is an n-type dopant), and yet this tiny addition accounts for such significant changes in the behaviour of the material. And so off I set onto the sea of electrons.

My journey took me deep into the world of angular momentums and exclusion principles, illuminations of virtual photons lighting my way, as I floated on surfaces of identical electron particle/waves. I had a smooth crossing of the Dirac Sea, since there was nothing there to cause wind or heavy weather, although the negativity got hard to bear towards its infinitely distant shores. Luckily the outcome from such monotonous negativity can only be positive, and all of a sudden the antimatter positron popped into existence. I journeyed on through radiant matter, and passed a few anomalous magnetic moments. Many hours of incomprehension further into the books and pages, all the while trying to assess which bits of this science are knowledge and which are model. I know that people have focussed beams of electrons for one reason or another, but no one has ever actually seen an electron, so know not what they have focussed. I read words telling me that an electron has a mass of about 0.00000000000000000000000000009 g, has an electric charge of -0.00000000000000000016 coulombs and a spin of a half. But I am also informed that electrons have no substructure and are hence assumed to be a point particle with a point charge and no spatial extent. I’m not sure how I can draw no spatial extent.

In order to see anything it seems that we need an illumination source that has a shorter wavelength than the dimensions of the thing we are endeavouring to see. For example, we can see using light since it bounces off the surface of visible things in such a manner as to convey surface texture and colour of objects, etc., to our eyes. Using a classic light microscope we can visualise objects with a resolution of down to about a tenthousandth of a millimetre, at which point the wavelength of visible light is getting to be of a similar scale to what we are looking at and it ceases to be able to discriminate surface variations. With an electron microscope the smallest dimensions visible are in the low nm range, about a hundred or so times smaller than things that can be seen under a light microscope. In order to look at an electron or a photon we need (a) for them to have a physical existence, and (b) something that can visualise down to the range of their physical size. 

And so I am back at wondering how, in the name of Art, to depict silicon’s electrons. Mentioning my problem to M later in the day she suggests that I simply put forward blank sheets of paper, and since she is an Art Historian I think I’ll take her advice.

12 July 2011

tiny profiles

(i do like a palindromic date) 
Back in the lab. Briefly. I bumped into L in the corridor, and asked if she was going to be in the cleanroom, which she was, and so asked if I could accompany her, which I could. So I did. Her task of the moment was to measure the thickness of a film on a substrate. She hence coated said substrate, which looks extremely like a piece of glass (about 1.5 cm square) by adding her solution (a clear one, a couple of drops) and spinning it for 30s in a centrifuge-type machine. All of this took place in one of the clean boxes with her manipulating the sample and equipment via the arm-long black rubber gloves (they are the arm equivalent of thigh-high boots, but I cannot think what the word to describe them in that way would be. Were they boots they would be very kinky – stretchy, close fitting, limb-long rubber - but as gloves they are somehow so very prosaic. Nonetheless I cannot resist the temptation to see how it feels.). I put my arm into one of the gloves, fingers into inverted fingers then rolling into it from there up – already ensconced in two pairs of shoe covers, a full length Tyvek suit, two hoods, gloves and spectacles I felt somewhat encumbered. Goodness only knows how they conduct any subtle actions buried under so many layers. Prior to working on her sample L had to get it into the clean box, which requires it going in through a little evacuated ante-chamber. This chamber was flushed three times with nitrogen gas (that’s what is in the clean box), and then the sample moved into the chamber. She explained her process as she went along, and I struggled to hear amidst the rustlings of many layers of clothing and background machine noise. L is working with Ravi Silva, who is the director of the ATI, and who works (in part) on solar cells, his group exploring new materials and methods to make them more efficient, longer lived, smaller, etc. After the transparent fragment is coated with the transparent coating L removes the sample from the clean box and scratches the surface, in order to be able to measure the profile across it. This is undertaken using a profilometer. A profilometer is basically a probe that is dragged across the surface of something and which records the topography of the surface. I love that kind of technology; I imagine it to have been around for hundreds, maybe thousands, of years in almost the same form. The form of this one is somewhat twentieth century, being a rather fetching brown and beige computer-looking machine. On the label it says 1994, but to me it is reminiscent of a computer my dad bought in the early 1980s, all ergonomic curves and a small, embedded, flickery screen. Apparently it is so knackered that they can’t switch it off, and must simply turn the brightness and contrast down. L measures the profile and I get caught up in drawing the machine – as ever in the cleanroom I am restricted to using the shed-free paper and biros and pens. In the university shop on the way in to the lab I had stumbled upon a cherryade-scented pen, and so my drawing becomes a multi-sensual event. The profiling completed L must go to have a meeting with Ravi. We leave the clean room, disrobing in the ante-chamber as we flush back into the audible, unclean world.

5 July 2011

prime days


A prime date. 

5, 7 and 11 are consecutive prime numbers, but I wonder if 5,711 is one too? I guess the internet would be able to tell me in a flash. But I am not online at the mo. Somehow 5,711 does sound a suitably awkward number that it may be a prime. Let me see – is it divisible to an integer by 3? No. 5, no, don’t need to use a calculator for that. 7? No, but that’s a nice looking number 815.857142857142857142... 9, no. 11? No. 13, no. 15? No. 17, 19, 21, 23, 27? No, no, no, no, no. I’m beginning to wonder if I am going to have to try every odd number up into the hundreds...  maybe so. 35 (being a multiple of 7?) has a similarly good looking answer at 163.171428571428571428571... The forties and fifties and sixties give no integer divisible solutions, but the numbers by which they must be multiplied to get to 5711 are falling, and drop below 100. When I get up to trying 73 the answer is in the seventies, which means that I must be nearly there. 75? No, that is a 76.146666666666666666666666666666666666666666666666666666666667th of 5711. And so, seemingly all of a sudden, I know that it is indeed a prime day.

Last week a trip to the museum at Porthcurno whilst in the area to drop off a silicon photonics drawing. Porthcurno is a small bay on the south coast of Cornwall, down beyond Penzance, where, from 1870 onwards, early international and transatlantic telegraph cables crossed from the land into sea; submerged copper wires taking messages around the world. The first successful trans-Atlantic cable had been laid between the UK and USA in 1865. Submarine copper cables were insulated using gutta percha, a substance similar to rubber, which had recently been discovered. By 1900 Cornwall was connected to India, North and South America, South Africa and Australia via such cables at Porthcurno. Messages were transferred using Morse, or other coded systems; text messages being distributed via a global network more than a hundred years ago. 

And some interesting art. A piece called ‘Soundings’ by Penny Nisbet at the Porthcurno museum (http://www.porthcurno.org.uk/), in which audio signals are generated from a dormant, but largely intact, submarine cable, since it acts “as a giant antenna in the sea of electromagnetic waves we are continually immersed in”. She further says “The prospect of the ancient telegraph cable resting silently on the seabed adds something to the fascination of listening to the sound of the radio energy it is receiving, including natural radio emissions of cosmic and atmospheric origin as well as those from man-made power sources.”

At the nearby Newlyn Art Gallery I pop in to a related exhibition of sounds and sculptures, co-curated by students at Falmouth Art College, called Down There Among the Roots (see http://downthereamongtheroots.wordpress.com for more info). In the Lower Gallery the sounds, by Chris Watson, include those made by hydrophones submerged “at the point where the ocean breaks upon the land and burying equipment into the earth beneath a series of wires”. These noises accompany Phoebe Cummings’ un-fired clay sculpture in a vitrine (and I must admit I’m a sucker for a vitrine – if your tastes are of a similar vein take a look at Marielle Neudecker’s tank works sometime) of a scene incorporating Malaysian Isonandra Gutta trees, producers of the aforementioned gutta percha. Upstairs, larger miniature un-fired sculptures of the Cornish landscape are accompanied by sounds captured from stretched wires in Australia and Cornish field recordings. And the view from the cafe, it being a sunny, turquoise-seaed, cloud-rushingly breezy day, provides other sensory fulfilment.

Art, science and Cornwall on a sunny day – a prime combination.

16 June 2011

Eye balls

Last week I was back in the lab again. A highlight of my time In Residence was sitting quietly drawing the experimental rig and an eye, while DT was back and forth conducting experiments on the ring resonator, answering my intermittent questions and explaining subtleties of the process. The setup was one that I am now familiar with, the laser light emitted from an electronic box on a raised shelf, passing through various optic fibres to the point where it meets the wafer, on a table that is damped from external vibration by means of hydraulic legs. The piece of silicon disc (wafer) is clamped down and the light carefully aligned along the microscopic silicon grooves and mounds etched within it to pass through, in this case, a ring resonator. This device modifies light. When first in the lab that sentence did not falter as it encountered my brain, but with time I am becoming more perplexed by the process of altering light; it seems a rather fundamental thing to do, even if technically simple, to change, for example, the wavelength of a ray of light.

The eye diagram is a standard output format for this type of work and is indicative of the level of clarity of binary information transfer, a widely open eye being a sign of good data transfer with a low error rate. DT has recently used one of his silicon photonics devices to transmit data at 40Gbit per second (with a modulation depth up to 10dB, which may be of interest to the initiated), which is pretty quick. (see http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-19-12-11507 for the paper) (Incidentally, “pretty quick” in the former sentence actually means unprecedentedly fast rates for optical modulation in silicon with a large modulation depth, and hence also useful in a practical sense). The eye was all seeing as I drew.

But it’s not all work. The lab meeting that I attend the next day is followed by a group tennis doubles tournament. My partner and I are the unrivalled losers, but strangely are the only pair to take a game off the boss and second in command (who, weirdly since they are the two best players, were drawn (by the second in command) to play together) – I think that we discombobulated them with our atrociousness. Or maybe it was simple pity (although I’m not convinced by this second suggestion, the boss has a penchant for fiendish spin which, when on the receiving end of it, doesn’t seem to have any possible connection with pity). (Is it possible that it is connected to the spintronics I’ve heard mention of around the ATI?)

As ever my return home is in a state of mental disintegration – the transition between these two worlds seems to have the kind of impact on me that I imagine teleportation would. And the tang of tennis weary legs on the train is a physical memory, reminding me that it seems I need to work on my tennis as well as my maths.

7 June 2011

Potential realities

The estuary at St Germans as stunning as ever, the bright sun glinting from the freshly rain-touched greenery and the river; the Tamar. Separating Cornwall from the rest of the country the beautiful inlets and waterways coming to a head, from the perspective of the train at least, as we pass over the Brunel Bridge at Saltash, and out to the sea beyond. As we cross the bridge I leave behind the gentle comforts of home, and pass the ‘realities’ of militarisation, dockyards, the urbanisation of Plymouth, heading into other versions of the world beyond, up country.

I have started reading Werner Heisenberg’s ‘Physics and Philosophy’, first published in 1962. In the late 1920s Heisenberg was famously uncertain about the possibility of knowing where anything is and the concurrent speed at which it is travelling, although, apparently paradoxically, was able to accurately know the probabilities of these attributes. Einstein was unconvinced by the idea of this fundamental unpredictability in the physical world, famously retorting “God does not play dice with the universe” to the notion. Heisenberg’s view, known as the Copenhagen interpretation of quantum mechanics, tells us that the observations of, for example, an electron, are what result in the existence of the electron. Measurement of the position of an electron creates an electron-with-a-position; test its momentum and an electron-with-momentum is created. An electron, in this view, is not a physical entity, but it and other fundamental particles “form a world of potentialities or possibilities rather than one of things or facts”. The reality, apparently, is the observation, not the electron.

And with such thoughts and words I am firmly back on my path into the world of electronic physics, striding out as if wearing high platform shoes with super-wobbly blancmange soles. Off I lurch, to observe the silicon photonics laboratory, wondering what art realities will result. It sure is good to be back.

11 May 2011

A pause

Due to circumstance there is a break in these words, in this process. However it will continue in June, and rather than wrapping up in August, as previously planned, the residency will instead continue until October. The next post will be on, or before, June 7th, so please come back sometime after that and see if this pause has proved to be thought provoking.

22 March 2011

Increasing the clarity of the unclear clearly

The light half.

Day 44. (already) A brief meeting with the boss. What a difference ten minutes makes. He has been reading the blog and is evidently appalled by the woeful lack of understanding and factual content therein; he specifically mentions the unclear “Clearly, this implies that...” which I referred to some weeks ago. It’s time for me to learn something. Only a few minutes later I leave the office with real comprehension about that formerly incomprehensible page turn (not least that the vertical lines either side of the letter r, the r representing the reflection coefficient, are the math shorthand for ‘the magnitude of’, so I can now at least write out the sentence in English rather than mathematics: Clearly this implies that the magnitude of the reflection coefficient is equal to one. (Why didn’t he just say that in the first place?)). But I’m also a little sad to have lost the infinitely intriguing imagined interpretation of imaginary numbers, having had them tied down to the mundane conceptual realities of axes on a graph (although as I write the understanding of why one would want to map the imaginary on the perpendicular axis to the real is again disappearing in a fog of misunderstanding, so that’s ok). Anyway, for the moment I don’t think it’s necessarily important to know the mathematician’s rationale for the perpendicularisation of real and imaginary, of import is that electronic engineers use the fact that real and imaginary numbers are plotted on the x- and y- axes (respectively) as an analogue for impedance in circuits. In capacitors the voltage and current are 90 degrees out of phase, and so these components (as well as the roles of resistors and inductors, the three collectively comprising impedance) can be mapped out on the axes (resistance is represented by the positive x-axis (the real equivalent), inductance by the positive y-axis (the imaginary equivalent), and capacitance the negative y-axis (imaginary equivalent). Bother, that seems to describe the roles of three of the four axes, but begs the question of what it is represented by the negative x-axis?). Anyway, it is evidently clear that by this means the overall impedance of a circuit can readily be calculated. You see?
As I write I am sitting on the train heading back home – again my reserved “window” seat was next to a piece of non-transparent train structure that largely obscures any view of the outside world, and someone else was already sitting in it anyway (having evidently also switched the seat tickets around to make it look like his!); but he is welcome to his falsely acquired sliver of view. It’s almost dark anyway, and I am now sitting at a forward facing window seat at a table, where I have spread out all over the place, and with relative acres of darkening glass next to me. I am riding high on the knowledge that I’ve acquired knowledge, and desperately trying to think of what to ask for the tutorial we have timetabled for next week; it seems that this art tomfoolery can remain obdurately obfuscated no longer.

16 March 2011

Miniscule devisive shoes

About time.

I left the house at dawn this morning, at that very moment of its occurrence. The blackbirds were just starting their chorale and the sky was lightening. As I travelled to the station the mist rested in the valleys, and hung in the trees on the hillsides; approaching the turning, a long view through to a low east horizon showed a disc of deep luminous red hanging within the grey fog, the sun making its local debut for the day, stunning. Even as I saw it the news on the car radio reported of the evacuation of the Fukushima Daiichi power station because of a “spike of radioactivity” following explosions and a fire. On hearing the news I am stupefied in sadness and horror – what we do to ourselves, what we do to this earth.

As I write I am en route back up to the lab, a two day stint of residing. The train creaks and trembles as it rattles along the warming tracks, the day outside increasingly sunny, the warmth and light burning off the vestiges of water vapour, giving the day a bright golden clarity. I have decided that the time, being half way gone, is apposite for revisiting the copy of nature photonics that Graham handed me that first trip to the University (the Silicon Photonics special, August 2010, volume 4, number 8). 

[Low tide at St Germans as we pass, the muddy slivers of estuary snaking between the breast-like hummocky hills.] 

I can still remember my first naive fumblings between its sheets, sitting in the doctor’s surgery waiting room, trying to make some sense of it and recording my wonder at the words. I wonder how the experience of the time spent so far amidst the silicon photonicists will have affected my abilities in that realm.

Even as I open the covers I can’t help the smile as I read the words “Towards fabless silicon photonics” – doesn’t it sound like they’re trying to take the fun out of it? and I’m afraid that “Mid infra-red photonics in silicon and germanium” just makes me think of the silicon geranium photos I have taken. But enough mucking around, time to redive into Reed, Mashanovich, Gardes and Thompson, and their small world of silicon optical modulators (pages 518 to 526).

[Unbelievably low tide on the Plym as we pass, the sunshiny mudflat thronging with birds; it is the equinox this weekend, so I guess we’re due big springs soon, but the moon last night was a bright and clear more-than-semicircle, so I should think it’s pretty much fully neaps. Perhaps we are passing at the moment of its lowest ebb.]

In the review abstract they report that “Modulators have been improved dramatically in recent years, with a notable increase in bandwidth from the megahertz to the multigigahertz regime in just over half a decade.”, which I think sounds pretty amazing when you think that such a shift must be supported by actual physical technological and fabrication developments (this latter the word responsible for the dour, truncated fab in fabless), as well as the conceptual and ideological drivers involved.

[I just went and squeezed in next to a guy facing the right way in order to take my customary photograph of the “Teignmouth Electron” as we passed (a long series of muzzy and largely imperceptible images of a
(currently rather rapidly and man-assistedly) decaying boat on the banks of the Teign). This “Teigmouth Electron” is a boat that is reminiscent to me of the real Teigmouth Electron, which is apparently slowly dissolving on a Caribbean beach, and to which I was introduced by a piece of Art made by Tacita Dean. In the book about it she tells the story of Donald Crowhurst who went out alone onto the watery surface of this world, on his final earthly journey, in the little vessel, on a partially-faked round the world race. It is a haunting tale that is beautifully told by her, delving into the realms of hope and expectation and time. An inspiring work. Just before he got off at Exeter the man came to thank me - he’d looked it up on the internet via his phone and thought it was a great picture (I recommended he look up the book and read the words...).  Very satisfying to have passed on the awareness of something wonderful, especially so geographically close to the location of the doppelganger craft.]

Back in the journal I grasp what the abstract is trying to tell me, although there are still some words that are yet mysterious. I am not clear as to what the modulation depth refers (I assume it is more than simply a physical depth in the wafer), and do not know how the energy requirement per bit can be altered, although with such increases in numbers of bits presumably it is something of a major consideration. As for the size of the device footprint, I do not know it but assume, given the scales at which they are working, that it must be very tiny, and very fast; miniscule devisive running shoes?

7 March 2011

Art in the lab

I had thought that suffering three years of what they refer to as teaching on a fine art BA had finished, once and for all, any desire for me to continue a relationship with formal education. However, last week I became the proud recipient of a certificate that enables me to be in the presence of multifarious lasers, and with only a little more tuition I may yet even be allowed to switch one on. The laser course, at a mere one and a half hours, was not the most painstaking of learning processes, and yet my name is printed on the certificated page (in a different font to that surrounding it) and the qualification valid for three years. Not only that but it was sunny pretty much all day. If I do ever work out how lasers work (and perhaps should mention that the jocular Spaniard assured me formerly that they shouldn’t) I will let you know. I had hoped that this blog post might be learned and profound (dream on?!), possibly even adding some insight as to how lasers do work, for example, since it marks the half way point of my residency in the silicon photonics lab. But instead I’m rather in the mood for a bit of Art.

For the lab meeting on Thursday I festooned the walls of the meeting room with photos and drawings that are some of the products of my work during the time I have been at Surrey (take a look in a couple of days at www.emmahambly.net for images, which will be placed there imminently!). They are a plethora of things, and some to me are beautiful. [A note to scientists at this point, the term beautiful was basically illegal at art college when I was there (one and two third years ago), since it was judged very low brow to make things that have aesthetic appeal which can be deemed as such. However, there may have been a subsequent cultural shift, as much more recently (one and a third years ago) a Turner Prize winner’s wall drawings were positively described as beautiful by the initiated critics.] Having explained to the lab group what the works were all about, it was time for a pop up exhibition in the ATI, and so I opened the doors to the science masses. There followed numerous interesting conversations, about photography and dyes and light emitters, electronics in paper, etc, which have left me with many fascinating avenues, which, I imagine, will not get explored to any great depth as a result of constraints of time. [Although I have managed to bend time on several occasions, I am still not entirely able to manipulate it fully to my advantage, and it seems that I’m bound by the laws of mundane physicality most of the time, and so sadly currently consider my ability to explore the world as being finite.] A hit with the aesthetic judge (a member of staff from the Arts office at the University) were the rather abstract Polaroid photograms; some having been illuminated by the naturally spectral light of a full moon, and some using electronically derived illumination (i.e. my phone screen light). And I think the boss liked the glass piece I made that is inspired by the integration of electronics and optics, and loosely illustrates a ring resonator. This week I am to take the same objects and images to an art audience (some students at Plymouth College of Art), and am intrigued to see  whether they garner a different response there. For now I am off to work on the big drawing I am making, and to see if I can master the stretching of time.

Here I planted some flower seeds yesterday, and even this morning, beneath the rays of the spring sun passing through the greenhouse glass, I can sense the burgeoning awakenings in the warm dampness of their earthy beds.

27 February 2011

Habitat under threat

A quiet couple of visits to the lab in recent weeks. The first spent droring, as Mr White might say; luxurious hours of concentration in the laboratory following leads and optic cables around the bench and through slivers of silicon, pencil lines describing the experimental set up; incident light, reflected light, invisible light from boxed sources.

Then this week, a day spent in the library: reading, thinking, listening to the quiet hum of productivity, and on another floor, among vending machines and current journals, the raucous chatter of excited communications. As I bathe in the gentle murmurings of this cosseting haven I am internally, viscerally, bemoaning the possible loss of this environment as a result of the increasing electronification of the world. It isn’t only ancient habitats that are lost with the incessant spread of humanity; we also wipe out our own, more recent, heritage as we go.

Having been fed on a diet of ejournals in a previous incarnation I decide to try to ‘take out’ my first ebook, but cannot get the system to work – I’m not sorry to be delaying that experience until another occasion. Instead I return to the clean room for some time spent in intimately deep visual communication with the sputter machine. Because of the particulate debris they produce I am not allowed to bring my pencil and paper in here, so must use the smooth blue sheets provided on the inside of the airlock doors, and a biro. Not normally my favourite drawing implement, but it seems to work ok, and I (dressed in a pale blue clean suit (deliberately matching my sheaf of paper?), overshoes, cap and purple rubber gloves) immerse into another world until I am asked to move my chair for the man to vacuum beneath it, using the amazing technicolor Dyson.

26 January 2011

A percentage of reality

Today a full day of physical work; gratifyingly tired. I am reduced to sitting on the floor to write as I don’t have the heart to shift either of the cats who are inhabiting the newly arrived chairs. His and hers, crashed out next to the stove. (I think that M + T, the kind chair donors, will feel that this is the appropriate hierarchy of users.) 
It’s dark and tonight’s scene is illuminated only by the light from the laptop screen and numerous flames, both naked and encased behind the mica windows of the aforementioned sizzling stove.

The book lies open at a page showing the title of section 2.3.
Phase of a propagating wave and its wavevector.
I can’t tell if it’s merely the rhythm of the words, or a combination of that with their subtle rhyme and alliteration, but I cannot help but roll the phrase around in my mouth for a while, feeling its sound. It feels good. And visually the veve (vera verity?) embedded in the last word is somehow both alien, and yet unspeakably perfect. 
Yesterday I spent much of the day with the book, revisiting things that I had glancingly encountered previously. I was making notes, reading around, and more fully understanding ideas that were being described to me. I realised I’d previously totally overcomplicated the notion of phase. What is phase? (– it helps, when dealing with this question, not to worry about wave particle duality implications, but just to consider light in terms of its wave properties - in my experience this shifts the understanding from mind-bendingly impossibly complicated to really pretty straightforward). It also helps to consider that the time element involved is fundamental – phase is the proportion of a periodic waveform that passes some reference point after a time t. Simple. So, on I skipped, frankly even feeling a little bit smug at how readily it was all going in this time. But.
Amazing that the simple act of turning a page can move one from lackadaisical absorption and regurgitation of information, into utter incomprehension. That thin layer from page 13 to page 14 has a sharp edge, and is followed by some maths. I stumbled around with a number of the equations, which I didn’t follow but felt that I should, and which culminated with the rather uncompromising words:
“Clearly this implies that:
r = 1
and that r is also complex and hence a phase shift is imposed on the reflected wave.”
I’m afraid the only thing clear to me at that moment was that clarity and I had parted company. (Maybe this ‘clearly’, as with other transparencies, is a relative term, and I simply had some kind of nonlinear response to the information such that my optical density increased with the intensity of the mathematics). But I do not wish to infer that the writings of Reed and Knights (or “the boss” as the former is currently known among intimate company) are in any way at fault – only moments earlier I had been applauding the inclusiveness of their fundamental introductions to various aspects of the subject. No, rather it was that the brain of the resident artist was not at its best, and seemed to fall at what is shamefacedly probably quite an easy hurdle.
An urgent injection of low brow was required so I returned to wiki, in an effort to ease the pressure on my head. 
The wiki silicon photonics page is not exactly what I would describe as low brow, and when I reach the statement that two-photon absorption “ ...is related to the Kerr effect, and by analogy with complex refractive index, can be thought of as the imaginary-part of a complex Kerr nonlinearity.[8] At the 1.55 micrometre telecommunication wavelength, this imaginary part is approximately 10% of the real part.[42]”, I decide that my efforts into comprehension of this realm are probably done for the day. I take a morsel of comfort from thinking that at least I get a little of what a wavelength of 1.55 microns implies, but my brain falters at trying to compute how one can calculate the size of an imaginary nonlinearity, let alone as a percentage of reality.

19 January 2011

Intrinsic mediocrity

I must admit that a few months ago I wouldn’t have envisaged the pleasure I would garner from time spent with “Semiconductor Devices, Physics and Technology” by S.M. Sze (whose name has such a delicious plethora of connotations attached). Admittedly this evening the pleasure is somewhat enhanced by warm murmurings from the newly-fixed stove (just in time for the cold weather this week, and after the dully unatmospheric electronic heating of Christmas), and a glass of a really rather nice Merlot. However, delving into the world of physical chemistry has a new glow these days, which it has acquired through the light of a desire to understand it, rather than it being an educational formality. But more of insights resulting from (Mr, Ms, Dr, Prof...?) Sze’s words at a later date.

I spent this morning sitting out on the deck, in the unstinting sunshine, finishing reading The Periodic Kingdom, and frankly now have a more fundamental understanding of the nature of chemistry than ever before, thanks to the combined work of Peter Atkins, who wrote the book, and Martin Blissett at the ATI who suggested / loaned it to me. (The more detailed reference for those who are interested is Atkins, P; The Periodic Kingdom, a journey into the land of the chemical elements; 1995; Weidenfeld &Nicolson, London). I have been doing some investigations into group IV chemicals over the last weeks (although P Atkins has now informed me that to comply with the IUPAC I should no longer refer to them as that, rather calling them group 14 chemicals, as proposed by the chemists’ committee), since this group contains, among other interesting things, silicon. Silicon, which is the subject of a significant chunk of my current intellectual and artistic endeavours, is a semiconductor (more about them anon), and as such is fundamental in the world of contemporary technology. But today the striking interest, to a biologist at least, is that carbon is also a group IV (or 14) element, and as a result of its properties as a member of that group has qualities that are indispensable for its role in living organisms. I’m going to quote Mr Atkins directly here, as I am taken with his description:
“... the overarching power of carbon to participate in molecule formation, a power that results in such complexity of structure and collaboration that the alliances it forms become alive and can reflect upon themselves [I think he’s talking about us here]. The essential reason for this latent power... is carbon’s intrinsic mediocrity, it’s lack of self assertion. ... it is neither an aggressive shedder of electrons, as are elements to [its] left, nor is it an avid receiver, like the atoms to its right. Carbon is mild in its demands on the alliances it makes. Moreover it is even content with its own company, and can make extensive liaisons with itself, forming chains, rings and trees of atoms. ... By being in the middle, undemanding and not particularly generous, it can spin lasting alliances rather than hasty conspiracies.”

I am under the impression that statistics, at a gross level, will always reduce the impact of extraordinary outliers by attempting to constrain them with the middling throng. As a result average will always be average, no matter how amazing it really is (although maybe I’m skewing this argument to a normal distribution). This notion saddens me, as I (along with the devil) see the wonder in the detail. And yet today I have been taking real pleasure from the thought that a fundamental prerequisite of life as we know it is the passivity of this rather unexciting element; that intrinsic mediocrity is one of the primary components responsible for the bickering goldfinches on the bird feeder, the snowdrops and violets that are pushing up in the garden, bursting with spring, the fire that warms me as I write.

11 January 2011

A photon of understanding

Fabulous date today. 11.1.11

I had hoped, among these words and lines, to track something of the acquisition of knowledge; to observe the process of my learning and pin it, splayed wide, onto this page. But it seems it is insidious, like love, and all of a sudden it is there, with the subtle details of how it arose forever smudged into hazy history. Not that I yet fully understand what it is that I go there to learn, but I believe I am further along that path than I had realised; the words I now read have new thoughts and meanings attached, my view has shifted. And as I tumble down this rabbit hole I see jars and objects on the shelves as I pass that contain wonderous galaxies of ideas and notions, the names of which, scrawled on their labels in myriads hands, I am beginning to recognise, and am able to envisage the taste of. (And yet I know I have a long way to travel before I land, with the bump cushioned I hope, at the end of this mysterious trail.)

I attended a lecture by Goran Mashanovich a few weeks ago, a senior member of the silicon photonics research group. (He is very interested in the process of learning, and uses contemporary, interactive methods in his lectures to encourage it, with the result that he teaches well and scores extremely highly with his students in their feedback). Anyway, I am out of practice at maths and have almost no knowledge of electronic engineering so the lectures of his I’ve attended have basically been beyond my comprehension (in this latter one he spoke of tea and pie circuits, which I’m afraid sounded more like social interactions, to me, than technological advancements). The maths of it was pretty straight forward (so it felt; so he later assured me) and yet still beyond my current capability (though not, I believe, beyond past capabilities), and I came away at the end of the lecture under the impression that I had nearly grasped it.

There was a girl on my fine art degree who made paintings about the sense of being able to feel proximity of objects in darkness, for example walking along a dark corridor and having a sense of the presence of the adjacent wall. I found her work intriguing, and was much taken with the notion of this sense. Somehow I left Goran’s lecture carrying what felt like an analogous feeling – that of almost understanding. I know that I did not understand it, and yet I felt that the point of absolute comprehension was close at hand. Is it possible to determine that? The degree of learning. Does understanding work as a smooth linear progression, where partial understanding is a real entity, decipherable as a distinct part of a bigger thing? Or is it attained in discrete units (photons of understanding?), in which case there is no such thing as partial understanding, and without having received a full photon of it (seeing the light?) one is none the wiser. 

Or is it, maybe, that photons work the other way, and even though at the moment at which a whole one is absorbed (etc) there occurs a luminating epiphany of some sort, nonetheless exposure to a partial one can still provide a sense of light to the receiver?

10 January 2011

Directional transparency

Transparency (and, as it transpires, this is also true of honesty) is not, after all, an absolute thing. It is a matter of the energy gap, apparently. My energy gap is such that I am transparent to X-rays and cosmic rays, but light and heat do not penetrate too far into me.

The passage of light (and other radiations) through things, or their absorption by things, relies on spaces of the right size being available for photons to be acquired as they interact with the thing. If they are not absorbed these radiations either pass on through (for example high energy cosmic rays) or bounce back off the thing being subjected to them. Light in the visible range bouncing off and scattering from things results in us being able to see them – the basis of visual observation. The leaves of the geranium on my windowsill absorb all but the green portion of the visible spectrum (and use this light for photosynthesis); the unused green light is reflected and scattered away, giving the appearance of a green leaf. The flowers of this fragrant wonder, however, absorb all but a beautiful deep crimson, a colour presumably used to entice aerial suckers to come and interact with the soft, velvety petal, to feed on the nectar offered up, and thus to pollinate the plant.

Optical fibres are made of silica (SiO2), which is transparent to visible light. Pure silicon is transparent to electromagnetic radiation of wavelengths greater than 1.1 micron, which is in the infrared, but is not see through in the visible range. Silicon is electrically ‘very good’, but this lack of visible transparency can, I believe, cause problems for those hoping to integrate electronics and optics in silicon.

Glass is transparent in the visible spectrum, so we can see through it (and thus use it for windows), and has a manipulating transparency to infra-red light, as a result of which we make greenhouses out of it and use it for passive solar heat gain in houses. (I must admit that I am unclear as to how heat can pass through a window one way but then not be able to get back out again – directional transparency? Imagine if the same thing happened with the visible light, my greenhouse would become brighter and brighter internally through the course of a sunny day (although I’m not sure we’d be able to see that light from outside the greenhouse – it would be blinding to walk into though), and then slowly the radiance would dissipate and diminish over night, as the light seeped back out into the surrounding dark).

4 January 2011

Invisible light

I walked from Trevan Point to the Rumps in the cold northerlyish wind yesterday; patchy sunlight between thick cloud, lowering to bright rays over the sea and a beautiful sunset. Seeing the colours of the burned-black gorse, fresh yellow flowers, bright turquoise of the wintery sea and myriad greys in the sky got me thinking about the light illuminating the scene. I always envisage visible light as colourless, and yet in reality it is comprised of all colours - every single conceivable shade is included in that transparent ray (or particle) that whistles past me, and of which a small portion is bounced back from the surface of the world to my receptors.

Funny that the light by which we see should be referred to as visible when it is, to us, invisible light.

First day of a new term today, for many; back to the process of learning, of knowledge acquisition, of education.