Photonics West 2007 opened Saturday amid a number of photonics-related advances, both commercially and in development, that are creating a great deal of excitement. BiOS 2007, the International Biomedical Optics Symposium, kicked off Photonics West and focused on lasers, molecular imaging, optics and bionanophotonics for researchers interested in life sciences, diagnostics and instrumentation. The event attracted medical and optical physicists, bioengineers, pharmocologists, cancer therapists, cell physiologists and hundreds of companies who exhibited instrumentation and devices that help them perform their work.BiOS, the International Biomedical Optics Symposium, offered opportunities for networking with colleagues in between courses, conferences and professional development sessions. (Photo: Photonics.com) "Judging from the crowds on the show floor and the number of business cards changing hands, it was a very successful exhibition indeed," said BiOS 2007's organizer, SPIE. "One gets the sense that biomedical optics is starting to receive the kind of frenzied attention that optical networking received in the late 1990s." "It should come as no surprise, then, that companies like JDSU have made aggressive forays into the biomedical optics space in recent years, most recently with their rollout of a new line of fluorescence filters for use in a number of biomedical instruments," SPIE said. Once consigned to the realm of science fiction, quantum-dot fluorophores and plasmon-enhanced photonics were, or would soon be, commercially available, SPIE said. "The 75 conferences, 75 courses, 1000 exhibitors and other special events and workshops that make up Photonics West have always been a good indicator, however, of how science fiction has a way of becoming science fact," it said. "The event is organized around four symposia: Biomedical Optics (BiOS), Lasers and Applications in Science and Engineering (LASE), Integrated Optoelectronic Devices, and Micro and Nanofabrication (MOEMS-MEMS). The Biomedical Optics Exhibition is held on Saturday and Sunday, and the larger Photonics West Exhibition begins Tuesday and ends on Thursday. Together it all adds up to the largest and most relevant photonics science and applications event in the world." Photonics West's BiOS Hot Topics sessions play to a packed house, giving participants the opportunity to discuss their optics- and photonics-based imaging and therapeutic research with attendees. "Biomedical applications represent one of the most exciting research and commercial growth areas for photonics," SPIE said. "Exciting imaging and therapeutic applications using novel forms of spectroscopy and tomography and more powerful, miniaturized and tunable sources have revolutionized the use of optics and photonics in the clinical and diagnostic spheres."Some vendors chose the well-attended BiOS exhibition at Photonics West 2007 to debut new products with scientific, biomedical and industrial applications. (Photo: Photonics.com) Among BiOS exhibitors was Japan-based Hamamatsu, which designs and manufactures optical and photonic detectors and sources for use in advanced manufacturing, telecommunications, biomedical optics and other applications; Lambda Research, which debuted TracePro 4.0, optical software for modeling fluorescence and light scatter in biological systems; Beijing Viasho Technology Co. Ltd., a manufacturer of DPSS laser in China used in scientific, medical, industrial and entertainment applications; and Headwall Photonics, a maker of imaging spectrometers and application-specific spectroscopy equipment for customers in the laboratory, test and measurement, and analytical industries. Headwall introduced the Raman Explorer 532, a high-performance Raman spectrometer based on Headwall’s patented, retroreflective concentric design. The product, using a 532-nm excitation laser, extends the capabilities of the Raman Explorer platform that is currently used in applications including space exploration, deep-ocean research and in-line process analysis of industrial operations. James Wyant of the University of Arizona was at the helm of a popular course on modern optical testing, which covers basic interferometric techniques used in the evaluation of optical components and systems. The Photonics West Professional Development Program began in earnest at BiOS, offering a wide variety of courses in optical coherence tomography, the fabrication and use of biochips, fluorescent sensing and diagnostics, tissue optics, optical system design and many other topics. Courses are taught by working scientists and engineers and are designed for those who work in production and sales environments to gain a fundamental understanding of a given optics- or photonics-related application, method or technology. The Multiphoton Microscopy in the Biomedical Sciences Conference, chaired by Ammasi Periasamy of the University of Virginia and Peter T. C. So of MIT, featured a talk by Ji-xin Cheng, of Purdue University, about endoscopic coherent anti-Stokes Raman spectroscopy (CARS) and "driving CARS into the biological field," in which he outlined the challenges of performing the procedure, including facilitating delivery of the excitation beam at the probe tip, collection of the return signal and understanding the resulting image. Last year, Cheng discussed the development of a Vanadate laser source; now Cheng and his colleagues are poised to do CARS imaging through a fiber. However, Cheng said, they still face substantial challenges, such as focusing the light that is backscattered from the sample target. To mitigate this problem, Cheng and his team had to design and develop a new delivery and collection fiber that incorporates a single mode delivery fiber and multiple multimode collection fibers. Dvir Yelin of Massachusetts General Hospital gave a talk on three-dimensional miniature endoscopy through a single fiber via spectral encoding that covered the engineering challenges of building the type of an endoscopic CARS instrument described in J-xin Cheng's research. The piezo scanning mechanism at the heart of the system is deposited as strips of PZT material on the fiber bundle. When these strips are electrically activated, the fiber bends. Through sinusoidal activation of the strips, the fiber can be made to spin in a circular or spiraling motion depending on the voltage amplitude. While this method possesses certain packaging advantages, it does not deliver the level of uniform illumination that the MEMS (microele tromechanical systems) mirror approach to scanning currently does, though the power requirements of the MEMS approach complicates the design of the system. David Kessel of Wayne State Univ., presented on Photodynamic therapy (PDT) death pathways. PDT is being considered for use in the treatment of carcinomas and sarcomas; This therapy would involve the creation of photosensitizers designed to bond to particular tumor cells, followed by irradiation with light of a particular wavelength, thereby initiating tumor necrosis. Kessel discussed three mechanisms under consideration by researchers: necrosis, known to be a highly reactive process that can cause death to neighboring cells and local swelling; apoptosis, which involves the destruction of the DNA in the cell; and the stimulation of the autophagic response, which causes proteins in cells to degrade. BiOS Hot Topics sessions -- one of the most popular special events at Photonics West -- gave invited speakers the opportunity to describe their R&D work in photonic-based imaging, clinical and diagnostic tools. This year's Hot Topics Session was moderated by Sergio Fantini of Tufts University and featured the presentation of a lifetime achievement award to Ashley J. Welch of the Univ. of Texas/Austin for his pioneering work on optical and thermal response of tissue to laser radiation. Sessions covered discussion on using infrared and near-IR imaging to optimize drug delivery and treatment. Thomas M. Baer, Stanford Photonics Research Center, raised the question of how optical imaging can be used to assist in the measurement of drug response. The question is not necessarily one of resolution but of measurement of critical parameters that can help the physician determine if a treatment is working, he said. Eva-Marie Sevick-Muraca of Baylor College of Medicine spoke of her work in IR fluorescence imaging as a promising approach for seeing the response of the body to drug applications in vivo. Her group has demonstrated lymph imaging 3-cm deep in animal subjects using NIR fluorescence techniques. Both of these methods could reportedly allow clinicians to monitor the flow and effect of therapeutic drugs to targeted areas. Christopher H. Contag of Stanford University discussed the need to develop targeted cancer therapies that have immunity to cancer cells. A number of optical imaging modalities are used to monitor this research, and a dual axis scanning MEMS mirror endoscope for in vivo imaging is being developed to assist in monitoring targeted therapies. Joseph A. Izatt of Duke University covered recent developments in Fourier domain optical coherence tomography (OCT). Using spectrally resolved OCT -- made possible by advances in mode locked fiber laser sources -- enables novel procedures like volumetric imaging and imaging of blood flow. Xiaoliang Sunney Xie of Harvard University extolled the benefits of CARS, including excellent spatial resolution and noninvasive application. New developments in laser sources also promise to enable CARS imaging at much higher resolutions, he said. Min Gu, Swinburne Univ. of Technology, spoke of applying multiphoton imaging, a nonlinear optical process, through and endoscopic system for internal imaging. For more information, visit: www.spie.org/pw