The BiOS portion of Photonics West kicked off this weekend, with the first day culminating in a lively Hot Topics session at the Moscone Convention Center here in San Francisco. Drawing a capacity crowd, the session focused on both clinical and basic science applications of optical techniques, featuring a broad range of presentations by researchers from throughout the field. On the clinical side, we heard about emerging technologies as well as modalities already in use. Alexander Oraevsky of TomoWave Laboratories Inc. and the University of Houston described how he and colleagues are working to translate 3-D optoacoustic tomography to clinical applications — through quantitative functional and molecular imaging, for example — while Laura Marcu of the University of California, Davis outlined efforts to develop time-resolved fluorescence spectroscopy for intravascular diagnostics. We know, of course, that optical coherence tomography is already widely used in ophthalmology — in terms of the volume of procedures done, it far surpasses angiography and fundus photography. But David Huang of the Casey Eye Institute at Oregon Health & Science University discussed developments in the technology, including those stemming from the introduction of Fourier-domain OCT, that will lead to further advances still. One of the hot topics here, he said, is the move into the operating room, as OCT has been incorporated into femtosecond laser cataract surgery systems by two companies already. Finally, Karsten Koenig of Saarland University and JenLab GmbH discussed the clinical potential of multiphoton microscopy — for example, for early diagnosis of human malignant melanoma in vivo. In fact, he said, multiphoton technology is already in clinical use in Australia, Japan, Europe the US. We also heard about exciting developments in the basic science arena. Paras Prasad of the University of Buffalo talked about an integrated biophotonics platform — incorporating, for example, coherent anti-Stokes Raman spectroscopy and second harmonic generation — that can help to elucidate the processes involved in cell-drug interactions. Ed Boyden discussed developments in optogenetics that might help to advance treatment of brain disorders (See also: Optogenetics: A Conversation with Ed Boyden). And Eric Mazur of Harvard University explored various novel uses of femtosecond lasers in biophotonics. The most poignant part of evening surely came early in the session, with tributes to a pair of giants in the field, both of whom passed away in 2010. Dasari Rao Ramachandra of Massachusetts Institute of Technology opened with a talk about his friend and colleague Michael Feld. He noted the myriad ways in which Feld impacted the scientific community — as director of the MIT Spectroscopy Lab (later the G.R. Harrison Spectroscopy Lab) from 1968 to 2010, where he made fundamental contributions to laser science among many other achievements; as a researcher with a gift for building collaborations; as a champion of equal opportunity — and then discussed in depth his work in sensing glucose by spectroscopy and imaging cells by tomography. Next, Bruce Tromberg of the University of California, Irvine and Arjun Yodh of the University of Pennsylvania paid tribute to Britton Chance, who passed away in November at the age of 97. In many ways "Brit" was a bit of a puzzle, Tromberg said. Anyone who came into contact with him couldn't help but ask, "Who is this guy? Why is he involved in so many things?" Associated with Penn since the 1930s, Chance studied physical chemistry and, later, biology and physiology; contributed to the development of radar during World War II; and of course helped to launch the field of biomedical optics. And he was spectacularly productive, Tromberg said. For a period in the 1980s, he was publishing between 50 and 70 papers a year, and he hit the 1000 citations per year mark as early as the late 1960s.