ABSTRACT
In order to reduce the effect of the in-orbit space environment on the optical system of a laser communication terminal, thus improving communication quality and tracking accuracy, an integrated primary mirror structure made of high-volume-fraction SiC/Al is proposed. It resolves a problem of stress concentrations arising as a result of using materials of mismatched coefficients of thermal expansion for the mirror and its support. The temperature stability of the primary mirror surface shape has been improved. On the basis of this work, a lightweight optical system has been achieved. Simulation analysis shows that when the temperature of the working environment changes by 20 ± 5°C, the Peak-to-Valley (PV) value of the surface-shape error is λ/16 and the Root Mean Square (RMS) value of the surface-shape error is λ/67. In a scenario in which the loading forces of gravity and temperature are coupled, the PV value of the surface-shape error is λ/16, and the RMS value of the surface-shape error is λ/63. The base frequency of the integrated primary mirror is 436 Hz, and it has improved dynamic stiffness. The structure can satisfy the requirements of the RMS value of the surface-shape error, λ/50, of a laser communication system, and provides a technical basis for follow-up research work.
