Study On The Methods Of Laser Spectral Measurement

With the rapid development of modern laser technology,spectral measurement of laser has become the research focus as the frontier of spectroscopy both at home and abroad. At present,the more research emphasize on how to obtain high-resolution spectrum. Based on the development and research status of the laser spectral measurement at home and abroad,the three types of methods of laser spectral measurement has been diescribed: Fourier transform type,grating diffraction type and Fabry-Perot type. Then the experiments of laser spectral measurement based on the fourier transform type and grating diffraction type have been performed. Forthermore,the expressions of the transmission peak wavelength and wavelength resolution of the Fabry-Perot type have been derived.Firstly,with the example of the Michelson interferometer,the principle of Fourier transform optics has been described,and the modified wedge interfering etalon and the static Mach-Zehnder interferometer have been introduced. A demonstration experiment of interference based on Michelson interferometer and the spectral measurement of 635 nm and 532 nm laser based on the modified wedge interfering etalon and the static Mach-Zehnder interferometer have been performed.The theory of laser spectral measurement with the grating diffraction has been analyzed,and spectral measurement of the 650 nm laser has been performed. Then,the expressions of the transmission peak wavelength and the wavelength resolution of Pabry-Perot interferometer have been deduced by the calculation. Finally,the advantages and disadvantages of previous methods have been summarized according to the experimental and theoretical calculation results. The Fourier transform type has slight measurement error,and easily implement laser spectral measurement. The wavelength that is measured by grating type is more precisely,but the range of spectral response is narrow. And the Fabry-Perot type has a high resolution of the laser wavelength, but it is not conducive to research spectral measurement of the laser that have a larger wavelength.