Nonlinear microscopy was introduced by Denk, Strickler, and Webb in 1990. They published in Science on two-photon fluoresence imaging and two-photon -induced photochemical reactions in biological cells. Today’s nonlinear microscopy in Life Sciences is mainly based on the application on near infrared femtosecond laser technology for fluoresence imaging, second harmonic generation (SHG), third harmonic generation (THG), and Coherent AntiStokes Raman Spectroscopy (CARS).
