It’s a good question, and one that everyone working in photonics has at one point found an answer to: what is it about this particular part of the electromagnetic spectrum that proves so interesting and worthwhile to form the basis of a career?
For me, admittedly in the early stages of such a career as I grapple with the nonlinear optical properties of nanomaterials and attempt to exploit these to develop better pulsed lasers for a PhD, it’s the sheer potential of light and light-based technologies that fascinates me. This might seem a bold claim, and in itself insufficient to tempt young scientists to the optical table and away from the seemingly-glamorous ‘city jobs’ that so often beckon. However, it’s true, and to prove this I’ll briefly outline the work experience projects I undertook as a student that convinced me – all optics-focussed, but not optics as I’d previously known it.
My introduction to photonics came when I was randomly, and very fortunately, assigned a school science project with a luxury car manufacturer, exploring how to drive white LEDs to carefully control their colour. The LEDs, which form part of the interior ‘mood lighting’, were designed to gradually turn on in a welcoming manner as the driver entered the car, and to fade away on exit, wishing them farewell. LEDs were also used to create ambient lighting of various hues to set the tone for the driver’s journey. Cruising along the motorway at speed? Perhaps you’d like a crimson glow to excite and energize. Or if driving the children home in the evening, maybe a warm orange hue will help happiness remain throughout the long journey? This really was a fusion of art and science to create the best possible user experience, highlighting that optical engineers need to not only understand the physics of electrons and holes recombining to emit light, but how this radiative recombination can influence human emotions (not to mention, their tendency to put their hand into their wallet for luxury goods).
From luxury items to everyday commodities, my next placement with a laser manufacturing research group challenged me to find a laser-based alternative to the common non-stick coating on frying pans: achieving fried eggs without the environmental concerns or costs of chemical coatings! Specifically, laser texturing of stainless steel was proposed to change how fluids interact with the surface. A focussed beam of high-power nanosecond pulses scanned across metal in a periodic pattern can create a surface microstructure of tiny micrometer-sized mountains and valleys, altering the surface energy. This can change the tendency for fluids to wet a surface, that is, whether a droplet will spread out and adhere to the surface or remain as a spherical droplet which can simply be wiped off. By making a surface more hydrophobic or lyophobic (water- or oil-resistant) as a result of laser texturing, it can arguably better resist stains and is more easily cleaned. Optical science played a role in all parts of this, not only in understanding the interaction of intense light and steel matter to modify the surface, but also in the engineering of a reliable source of high power laser pulses.
Finally, out of the frying pan and onto the golf course: my last work experience project with a local university proposed an investigation into optical methods to find lost golf balls in long grass. In America alone, it’s reported that 300 million balls are lost a year. Therefore, a device to retrieve these could have significant commercial appeal for the less experienced (/less able) golfers. As humans, we rely on visible light for our basic sense of sight to find and identify objects. But photonic technologies can operate beyond this fairly narrow visible region of the spectrum and this offers many new opportunities. One technique I explored was thermographic imaging using infrared light: since grass transpires to cool itself slightly, compared to an inanimate ball, lost items could potentially be detected by measuring this temperature difference. I achieved limited success with this over a short distance, so while the product might not be on the shelves of your local sports supplier anytime soon, the project did show that there’s much more to photonics and other ways to use light than simply in the visible spectrum.
Perhaps then, the best answer to my original question is in fact, “why not light?” Photonics is a truly multidisciplinary field, impacting upon every branch of science and engineering and affecting our daily lives so immensely that we often take it all for granted. So my advice for any aspiring young scientists or engineers out there would be to try photonics – there are so many companies and research groups out there who could offer a fun work experience project and who knows what you’ll end up working on: perhaps imaging cells to identify and treat cancer? Or creating more powerful lasers to achieve nuclear fusion? Or maybe, just making better fried eggs.
Note: All images were taken by the Author or from copyleft /royalty free sources.
Robert Woodward (firstname.lastname@example.org)
Robert is a PhD student at Imperial College London, researching nonlinear optical effects in optical fibres and nanomaterials for the development of pulsed laser and supercontinuum technology.
He is also a co-founder and current president of the Imperial College London Optical Society, an OSA and SPIE student chapter, aiming to promote the science and application of light at Imperial and to the wider community.