1. Field of the Invention
The invention relates to a plural third harmonic generation (THG) microscopic system and method, in particular to a plural third harmonic generation (THG) microscopic system and method applied to bio-molecules in vivo and medical engineering.
2. Description of Related Art
The technique of third harmonic generation (THG), with the advantages of having no light harm, no light bleaching, high penetrating depth and having resolution of sub-micron, has been widely applied in research of bio-images. The harmonic generation microscopy disclosed in U.S. Pat. No. 6,922,279 is directed to a microscopic system making use of a third harmonic generation incorporated with a second harmonic generation and having no fluorescent light, and is focused on the application in bio-medicine. As revealed in an essay published in “Resonant Frequency-domain Interferometry via Third Harmonic Generation,” Optics Letter 32, 1265-1267 (2007) by D. S. Stoker, J. W. Keto, J. Baek and J. Ma, the THG is also applied in the spectrum science to understand the structure and characteristics of the material or bio-molecules. However, such research is more or less insufficient with respect to imaging of bio-molecules, due to that the existing THG microscopic system merely provides a harmonic generation image with a single wavelength. That is, measuring the strength of the THG and then mapping the same to form an intensity image. As a result, only the morphalogy of the bio-cells and bio-tissues can be known. Further, the existing research of applying the THG in the spectrum science makes use of directly modulating the wavelength of a laser beam to obtain a spectrum of the THG, while unable to provide spatially distributed related information and unable to provide the function of simultaneously presenting a plurality of THG images.