In order to ensure the on-orbit performance of space laser communication terminal(SLCT), the optical performance test under thermal vacuum conditions must be completed on the groud. In this paper, according to the requirements of SLCT, thermal vacuum optical performance test system was designed and developed. Its main testing capabilities include the divergence angle, polarization state, wave aberration, transmission power. Several SLCTs were tested by the system, the results show that the overall performance of the test system is stable and the thermo-optical test of SLCT can be completed well.
Dues to its large capacity of information, super-speed transmission and high stability, laser communication has become a popular kind of satellite communication technology. Different from other kinds of communication technology, laser communication terminals (LCT) consists of optical systems with high imaging quality, high precise and rapid tracking systems. Testing the LCT on land is necessary to ensure its performance on the satellite. This article introduces a LCT-test and evaluation station (LCT-TES) in the laboratory. The LCT-TES is a high quality optical system providing laboratory measurements of the key characteristics of LCT, such as power testing, energy distribution of light spot in the far field, and the angle of beam divergence. The test precision of LCT-TES is also analyzed in this paper.
For a wavefront tested by Shack-hartmann wavefront sensor, the zonal integration method is often chosen by researchers to solve the reconstruction problem. But it has shown an unacceptable result when the phase derivative data is distributed on an unconnected domain, the obtained wavefront will contain different piston error on each subdomain. Therefore, a new zonal wavefront estimation algorithm is proposed to deal with this drawback, which uses a simultaneous fit method to correct piston error of each subdomain. The validity of the algorithm is verified by a numerical simulation and experimental results.
Absolute measurement with Phase Measuring Deflectometry (PMD) is gaining importance in industry, but the accuracy of deflectometry metrology is strongly influenced by the level of calibration. In order to improve the accuracy of the PMD to a level where it competes with interferometry, a reference calibration process is commonly carried out to carefully calibrate the systematic errors. The systematic errors obtained by measuring a high quality reference surface can be subtracted from the measurement of a test surface to get its actual surface, however, it could introduce the surface error of reference into the measurement. To alleviate this problem, this paper introduces a technique named “rotational shear phase measuring deflectometry”, this technique have the ability of removing the rotationally asymmetric systematic errors from the test surface without using a reference surface. The validity of this technique has been demonstrated by simulation and our experimental results.