Mechanism Of Second Harmonic Generation In Biological Tissue

Second harmonic generation(SHG) imaging needs no fluorescent labels and brings no photobleaching or toxicity. It's a promising tool for high-resolution, three-dimensional studies in biomedicine fields. Now, in despite of many experiments and some explanations about SHG in biological tissues, owing to the complexity and variety of biological tissues, to some extent some explanations were with hypothesis, the mechanism of SHG in biological tissue is not clear all the same.In this thesis, some SHG experiments are made in rat-tail and fat. Preparation of samples, laser wavelength, laser power and so on, can influence SHG in bio tissue. And SHG of longitudinally different layers are varied. SHG and two-photon excitation fluorescence(TPEF) images are also be observed in rat-tail and fat. The key in this dissertation is making some new comments on the mechanism of SHG in biological tissue on the base of the experiments and others' theories.