SPRC's Ginzton Laboratory provides the focal point for that programme and an interdisciplinary research team that comprises around 40 professors and 200 graduate students and postdocs. Theirs is a wide-ranging brief - SPRC working groups span microscopy, neuroscience, information technology, telecoms, integrated photonics and solar cells - though with a common objective: to partner with industry to bring innovative photonic technologies to market.
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, a big laser manufacturer 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, a leading professional association for optical scientists and engineers.
Joe McEntee met up with him at the Ginzton Laboratory to find out more about the SPRC's research and the long-term prospects for photonic technologies in biological and medical applications.
JM: How would you summarize the SPRC's approach to photonics research?
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 Stanford does this as well as any other university, certainly in the US.
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 also 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?
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 and efficient sources/detectors in new areas of the spectrum - coming together to solve a wide range of scientific and commercial problems.
Against that backdrop, 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.
Presumably, SPRC's biophotonics programme is a case in point?
Absolutely. A striking example of this convergence can be seen in biophotonics, 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.
We've also got a significant research programme here applying micron- and submicron-resolution imaging technologies, alongside what we know about molecular biology, to the study of stem cells. Although it's still in its formative stages, this research will enable us to better understand the developmental biology of stem cells and map out the fundamental processes associated with cellular differentiation and organ development.
On the clinical side, Chris Contag and his group here at Stanford 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 photonic technologies - for example, in diagnostic imaging?
If you talk to medical imaging people today, you find that they're overwhelmed with data, whether it's CT, MRI or PET. 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 seconds. That's extremely fast and generates half a gigabyte 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 instruments to measure structure, optical technology 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.
Can you highlight a clinical scenario where such an approach might prove beneficial?
A good illustration of the need for this "meta-technology" approach is in the early diagnosis of lung cancer, a disease which kills more people every year than the next three most deadly cancers combined, and which results in the deaths of over 0.5 million people per year worldwide. A recent study suggested that high-resolution CT scanning used in a screening regimen can potentially reduce lung-cancer deaths by a factor of 10 by detecting lung tumours at a very small size, under 5 mm.
One of the major challenges, though, is that it is difficult to distinguish lung tumours at that size from other more relatively benign lung nodules caused by common infection or diseases like TB. Using computer-automated 3D image analysis, and combining the CT data with data from other imaging instruments like PET scanners, clinicians can achieve a very low rate of false-positive diagnosis.
It is this combination of automated analysis of large data sets and the use of multiple imaging modalities to achieve accurate diagnosis that will lead to effective methods for early intervention in these types of deadly diseases. Whereas today we typically wait to treat the patient until after symptoms have appeared, which is often way too late.
What sort of work is SPRC doing on therapeutic applications of photonics?
We have a research group headed by Daniel Palanker that's very active in developing laser technology for ophthalmology, evaluating different pattern structures for cauterization of blood vessels in the treatment of diabetic retinopathy (a complication of diabetes that causes reduced vision and blindness through damaging changes in the blood vessels in the retina). Palanker's group also has a fascinating project to realize an artificial eye, looking at ways to implant inorganic photosensitive devices (CCD chips) to allow the natural growth of the visual cortex structures necessary to interface to the human brain. This research is fundamentally related to stem cells and developmental biology - and specifically, how the human body responds to injury by regenerating tissue, using cellular proliferation and cell differentiation to compensate for injury.
Biophotonics is an area that's characterized by plenty of technology push. How is that going to be translated into clinical pull?
What's going to be critical is a better interface between practising clinicians and technology developers. We really 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 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.