Evaluation Method Of Laser Beam Quality And Measuring System Of Laser Beam Parameters

Several traditional methods of evaluation of the quality of the laser beam are introduced and their traditional methods of laser beam quality's evaluation are introduced and their shortcomings are pointed out based on Gaussian beam's transmission characteristics. To be the scientific and rational evaluation of beam quality standards, M~2 factor is pointed out with the moment theory introduced, and at the same time, the beam parameter's formula is deduced.According to Lagrange-Helmholtz invariant and the properties of Gaussian beam's transmission, two 45°HR mirrors are dragged by high-precision controlling platform, laser's spot size of different axial positions can be measured. Detector is a wide spectral range, high SNR, high resolution near-infrared CCD. According to the different axial position's spot size, the hyperbolic equation is fitted, and laser beam's quality is given. He-Ne laser's beam quality is tested by the laser beam quality measuring system developed.The marking method of semiconductor laser's cavity surface emission station is put out. Image change tube which has large detection area is used to solve the problems of large divergence angle and asymmetric laser beam's parameter measuring.Semiconductor laser's near and far field measuring system is developed based on Image change tube , VCSEL and edge emitting laser's near and far field are displayed.