Experiments directed towards a clinically useful optical imaging system use long-pulse near-infrared lasers and a correlation time gate based on degenerate four-wave mixing in a nonlinear medium.

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors have demonstrated the use of a degenerate-four-wave-mixing time gate to allow imaging through turbid media, with potential application to tissue imaging. A near infrared (NIR), long-pulse Cr{sup +3}:Li2SrAlF6 laser was used as the light source (during most the project) for imaging through clear and turbid media. Preliminary experiments were also carried out with a continuous diode laser.

The use of light for probing and imaging biomedical media is promising for the development of safe, noninvasive, and inexpensive clinical imaging modalities with diagnostic ability. The advent of ultrafast lasers has enabled applications of nonlinear optical processes, which allow deeper imaging in biological tissues with higher spatial resolution. This book provides an overview of emerging novel optical imaging techniques, Gaussian beam optics, light scattering, nonlinear optics, and nonlinear optical tomography of tissues and cells. It consists of pioneering works that employ different linear and nonlinear optical imaging techniques for deep tissue imaging, including the new applications of single- and multiphoton excitation fluorescence, Raman scattering, resonance Raman spectroscopy, second harmonic generation, stimulated Raman scattering gain and loss, coherent anti-Stokes Raman spectroscopy, and near-infrared and mid-infrared supercontinuum spectroscopy. The book is a comprehensive reference of emerging deep tissue imaging techniques for researchers and students working in various disciplines.

SPIE Milestones are collections of seminal papers from the world literature covering important discoveries and developments in optics and photonics.

This entry-level textbook, covering the area of tissue optics, is based on the lecture notes for a graduate course (Bio-optical Imaging) that has been taught six times by the authors at Texas A&M University. After the fundamentals of photon transport in biological tissues are established, various optical imaging techniques for biological tissues are covered. The imaging modalities include ballistic imaging, quasi-ballistic imaging (optical coherence tomography), diffusion imaging, and ultrasound-aided hybrid imaging. The basic physics and engineering of each imaging technique are emphasized. A solutions manual is available for instructors; to obtain a copy please email the editorial department at [email protected].