The laser irradiation effect of three-junction GaAs solar cell arrays was studied through the experiment of fiber laser irradiation under different irradiation time and power density. The photocurrent voltage characteristics of solar array before and after laser irradiation were tested, The dark current voltage characteristics and spectral response of each solar cell array after irradiation were tested. The test and analysis results reveal that, The radiation damage of continuous laser to the array, due to the uneven energy distribution of the laser spot, the damage degree at different positions of the array is different. The damage of a single battery varies greatly, ranging from slight damage to complete failure. In the area with medium or strong laser power, continuous laser first damages the first and second junctions corresponding to the top cell and the middle cell, while the third junction corresponding to the bottom cell has less influence; In the area with weak laser power, the damage to the battery interior caused by continuous laser starts from the bottom battery with the smallest band gap, followed by the top battery and the middle battery.
In the simulated vacuum environment of low-temperature and low-pressure, a continuous laser irradiation effect experiment of 1070 nm was carried out on a carbon fiber composite sandwich structure with white paint on the surface of the reflector antenna using a fiber laser as the light source and the morphology characteristics of sandwich structures under different laser loading conditions were obtained. The transient temperature field on the surface of the sandwich was measured by a high temperature infrared imager, and the surface temperature rise of the sandwich was obtained by thermocouple. The relationship between temperature and damage morphology of structural materials was obtained by analyzing the changes of surface temperature field and morphology during laser irradiation. The mechanism of laser action on the sandwich structure of carbon fiber composite and the influence of laser parameters on the morphology of structural materials were studied. The results show that under laser irradiation with a laser power density of about 20 W/cm2, the white paint sprayed on the surface of the front skin first ablates and falls off. As the temperature rises, the resin base of the carbon fiber composite is pyrolyzed, the carbon fiber spallation occurs, the front skin loses its mechanical properties, the rubber film is pyrolyzed, the front skin is separated from the aluminum honeycomb, and the back skin expands and deforms under the action of pyrolysis gas.
Adaptive optics systems are highly complicated networks of devices that makes an analytical study of such systems difficult. Hence numerical simulations are crucial in providing a quantitative evaluation of capabilities of adaptive optics systems. The integrated simulations of atmospheric turbulence, wind profiles, Fresnel light propagation, model of Shack- Hartmann wavefront sensor, and wavefront reconstruction are done, and the aim is to simulate adaptive optics correction process and investigate the atmospheric turbulence and Shack-Hartmann sensor parameters on optimal results. The results of simulation of light propagation through turbulent atmosphere are presented.
The coherent addition of multiple beams is one of the great challenges in terms of large-scale lasers. Implementing the capability to generate ultra-high-focus power intensity on the focal plane places stringent requirements on the control of each beam’s pointing and intra-beam phasing. The random beam-to-beam phase jumps, mainly induced by the catoptric elements’ rapid vibration, should be eliminated to realize phase locking. A two-way laser beam’s coherent combination test bed is designed to test the capabilities of phase-locking system. The results show that the closed-loop feedback system achieved a high contrast of the in-phase intensity pattern at the receiving plane after correcting for piston and tip/tilt errors between two adjacent laser beams by the stochastic parallel gradient descent algorithm.
The stability of phased-array optics is a crucial issue for far-field focal-spot quality. The tiled approach of phasing optical elements is a widely used technique. Here it is adopted to maintain the long-time stability of a tiled system by a proportional-integral-differential (PID) algorithm. Experimental data is taken with 2×1 tiled-flat square mirrors driven by 3-axis piezoelectric actuators. The feedback frequency is over 80 Hz and the displacement error is below 4 nm. The optical measurement results show that the state-locked operation is continuously maintained for hour-long periods in PID control mode.
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