'Multidisciplinarians' are the future of photonics

Managing that technology-transfer process is a role for which Baer would appear well suited. After all, he has more than 25 years of front-line commercial experience to his name at companies like Spectra-Physics, where he was vice-president of research, and Arcturus Bioscience, a start-up that he co-founded to commercialize a laser-based gene biopsy technique. He's also president-elect of the Optical Society of America (OSA), a leading professional association for optical scientists and engineers.

Joe McEntee met up with Baer at the Ginzton Laboratory to find out more about the SPRC's research and its close collaboration with industry.

JM: How would you summarize the SPRC's approach?
TB: The SPRC reflects the research culture here at Stanford, which has been cross-disciplinary for many decades. Probably one of the key things about Stanford – and what differentiates it from a lot of academic institutions – is that it really looks at innovation as one of its core values. By innovation, I mean taking science and theory and making practical inventions out of it. I think that Stanford does this as well as any other university, certainly in the US.

Light work

SPRC's partnerships with industry are central to its mission. What's in it for your corporate partners?
A sizeable slice of the research at Stanford is contract research funded by industry. We've got roughly 20 industrial partners in our affiliates programme at SPRC. Around half a dozen are local (Silicon Valley), around half a dozen are from Asia, and the rest are distributed throughout North America and Europe. The affiliates actively support the research programme – they don't just give their name to us or sponsor a meeting. At the same time, we act as a talent pool. The affiliates know the primary products of Stanford are not only its research, but also its students.

In what ways does the cross-disciplinary emphasis add value to the SPRC's research?
A multidisciplinary effort is more than a bunch of people from different disciplines working together. It's a team of multidisciplinarians. You really need to encourage the physicists to learn the biology, the engineers to learn the chemistry and so on. That's what I found in the private sector. The most effective teams are the ones where you train the physicists, biologists and engineers to become very effective in cross-disciplinary work.

Solar energy is touted as the next big thing by optics industry insiders. Do you agree?
One of the technologies that we've spent a lot of time fostering at SPRC is solar energy. It's become a strong area of investment in Silicon Valley, the fastest growing in fact. We've got around 50 people working on photopolymer materials, device characterization and system design. Underpinning that work is this wonderful integration of nanophotonics, metamaterials and classical materials development.

Presumably the prospects for solar energy boil down to cost per watt versus conventional energy technologies?
Very much so, and what's exciting to see is that these are the challenges that are being addressed by optics researchers and industry developers. Fundamentally, the R&D community is looking at new materials for lightweight substrates that will reduce cost of installation and the overall life-cycle cost of solar-energy systems.

Think solar

What about your work in more traditional areas such as fibre-optic communication?
There's continued evolution here too. Work on 40 and 100 Gbit/s transmission is a big focus at SPRC. Specifically, there's research in silicon photonics to figure out how we can couple both the source and modulation technologies more effectively to the electronic signal-processing ICs. At the same time, we're also looking at 10 Gbit/s technology and how that can be more effectively deployed. For example, we're looking at 10 Gbit/s networks based on multimode fibre and how you can encode/decode information over an almost incoherent pipeline.

Are there any common themes that you see emerging across SPRC's different fields of activity?
If you look at what's happened in photonics over the last decade, it's like a second renaissance. The 1960s and 1970s were all about the evolution of the laser into the flavours we have today. There's a similar type of renaissance going on now with all manner of enabling technologies – metamaterials, MEMS, photonic crystals, efficient sources and detectors in new areas of the spectrum – coming together to solve a wide range of scientific and commercial problems.

A striking example of this convergence can be seen in biomedical optics, where scientists are coming up with remarkable insights into basic cell biology. Mark Schnitzer's team here at Stanford, for example, is exploiting ultrafast lasers in two-photon microscopy to study calcium pulses and fluxes in the neural pathways of the brains of living, behaving animals. Using photonics, we're actually decoding the circuitry of the brain and watching it happen in real time – in effect, reading the thoughts of these animals. It's a phenomenal advance in our ability to model what the brain is all about.

Also at SPRC, Chris Contag and his group are doing some remarkable work using viruses to attack tumours. They're then monitoring the "kill power" of those viruses non-invasively using real-time bioluminescence that's been genetically engineered into the living organism. Here again you see this coming together of enabling photonic technologies.

How would you rate the prospects for clinical applications of optical technologies – for example, in medical imaging? If you talk to medical imaging people today, you find that they're overwhelmed with data, whether it's computed tomography (CT), magnetic resonance imaging or positron emission tomography. All of these modalities have photonic elements to them, if nothing else just in the display of the information.

What I see as the challenge – and an exciting one in the interdisciplinary sense – is the interpretation of medical images now that we can get down to the order of a few hundred micron resolution and do a full CT scan of the whole chest cavity in 2.7 s. That's extremely fast and generates 0.5 Gbyte of data in 3D – more than the human visual system can take in.

What we need to do as a technology community is to develop the analytical tools to be able to extract relevant clinical information and render it in such a way that a clear diagnostic decision can be made. In some cases, this will mean a combination of technologies. For example, CT to measure structure, optics to measure function (parameters like blood oxygenation or vascularization), yielding a set of metrics that can be used to characterize whether something is benign or malignant. In effect, the optical technologies will provide an ability to measure along a different coordinate – the functional coordinate.

So you're talking technology push, but also clinical pull?
What's going to be critical is a better interface between practising clinicians and technology developers. We need to get the clinicians and the technologists together and that's one of my priorities when I take the helm at the OSA next year, establishing direct relations with clinical professional societies like the Radiological Society of North America and the American Association for Cancer Research. There's a parallel to the work that I do at SPRC getting industry working with researchers.

To round off, what advice would you give early-career optical scientists and engineers?
Photonics is an enabling technology – like electronics – in that it has so many different fields where it can be used. Something I instil in SPRC students from the off is that if they can learn more than one discipline it really distinguishes them. The more unique fields of enquiry you have knowledge of, the more you become unique in the eyes of your employers. Multidisciplinarians are the future of photonics.

• This article originally appeared in the May 2008 issue of Optics & Laser Europe magazine.

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