Biomedical optics is a rapidly expanding eld, which is providing new ways to detect, diagnose, and study the disease (Wang 2007). Optical methods allow one to study intrinsic signals associated with endogenous chromophores such as hemoglobin, as well as extrinsic signals associated with targeted exogenous probes. ey use nonionizing radiation, are low cost, and are extremely sensitive to variations in chemical concentrations and environments that allow both biologists and physicians to assay tissue function and monitor dynamic biological processes. ere are many optical imaging techniques commonly used in biology and medicine. Laser scanning confocal microscopy provides high-resolution, depth-resolved, three-dimensional images. Techniques such as two-photon uorescence microscopy and second harmonic generation microscopy, whose dependence on the applied light intensity is nonlinear, achieve even higher resolution and deeper penetration into tissues. Optical coherence tomography (OCT) forms cross-sectional images of tissue scattering by detecting the interference between backscattered light from the sample and light from a reference beam.