Power stability control based on white laser

Abstract

Aiming at the stability control requirements of high stability solar simulation light source, a white laser power stability control method based on quartz is proposed. The quartz plate is connected and fixed with the scanlab, and the relationship between the Angle of the incident light and the transmittance is taken as the signal regulation principle. When the scanlab rotates the quartz slab, the light signal transmitted by the quartz slab is adjusted. Based on Fresnel's Law, the rotation Angle and transmittance parameters under different wavelength of incident light are analyzed. And the rotation Angle range of quartz is calculated, which provides the output parameter support for realizing the power stability of light source. PID algorithm is used to modulate the error of the signal of the monitoring detector and the voltage corresponding to reference power so as to accurately adjust the output of scanlab. The stabilizer is used to control the power of the white laser, and the Trap detector is used to verify the level of power stability. The experiment results of the stability of the laser after modulation is as follows: the standard deviation C_V is 0.069%/55min and the peak-to-peak fluctuation S_V is ±0.302%/55min. Compared with the free-running result, S_V and C_V are improved to 1/15.83 and 1/33.04 respectively, and the power stability of the white laser is enhanced, meeting the stability requirement of 99.6%.