| With large optical nonlinearities, semiconductor materials are widely used in laser, optical switching, optical limiter, optical signal processing, and so on. The new Ⅲ-V group compound, direct band-gap semiconductor-In N has many advantages: high carrier and surface electron concentration; fast electron mobility. Thus it has great potential applications in infrared optoelectronic devices and nonlinear photonic devices.To date, the research in terms of optical nonlinearities of In N concern thin film materials, in this dissertation, the nonlinear optical properties of In N lump material have been studied by reflection Z-scan(RZ-scan) technique in visible range, and combined transmission Z-scan(TZ-scan) technique with femtosecond laser pulse the nonlinear absorption property of infrared wavelength is further studied.In this dissertation, starting from the theory of RZ-scan technology, the condition of ignoring the contribution of absorption to open-aperture RZ-scan is obtained by analyzing the effect of linear refraction, linear absorption and the angle of incidence to the reflected beam energy of open-aperture RZ-scan. The method of moving the lens is feasible and much better than moving the sample through analysising the experiment results of translucent semiconductor material Zn Se using picosecond TZ-scan in cases of moving the lens and sample, combined with sample moved RZ-scan technique. Using RZ-scan technique with the method of moving the lens, the optical nonlinearities of In N at 532 nm are studied, the experiment results show that there exist strong nonlinear refraction and saturable absorption under picosecond pulsed laser. The strong nonlinear refraction measured suggests that it may be a material with potential application in optical switch. Using TZ-scan technique, the nonlinear absorption property of In N at 1030 nm under femtosecond laser pulse is studied, band-filling effect induced by linear absorption creating saturable absorption is observed. |
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