The performance of the free space optical communication system is influenced by many factors, such as the safety standard of the laser products, the transmitting characters of laser, the wavelength of laser and the background noise.
In recent years, the relevant departments have been actively publicizing and implementing this standard, and supervising and inspecting seriously the quality of laser products, including laser instruments and devices, to meet the safety standard.
By taking the LD-pumped all-solid-state Nd:YVO 4 gree n laser with a sandwich resonator for example, the relationship between far-field scattering angle and the error of the laser crystal with the vertical plane of t he optical axis was studied. The result shown that this method can check the pas te quality of the laser crystal by quantity and can raise the productive efficie ncy of laser products greatly.
The relationships between focal length, oriented error of focal plane of the mirror and span, optic axis parallelism of the laser products are described.A method for orienting more precise position of focal plane is presented.