Handbook of Biomedical Optics

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27.1 Introduction

In 1990, the publication of “Two-photon laser scanning uo-

rescence microscopy” in Science by Denk, Strickler, and Webb

has ushered in an era of unprecedented growth in apply-

ing nonlinear optical principles in biomedical microscopic

imaging and manipulation (Denk et al. 1990). Two-photon

microscopy, as described by Denk and coworkers, is based on

uorescence contrast and remains the most important and

widely used form of nonlinear optical microscopy in biomedi-

cine. Today, more advanced techniques based on other nonlin-

ear processes, such as second (Gannaway and Sheppard 1978)

and third harmonic generation ...