Design and analysis of the opto-mechanical structure for an airborne laser expander system

In response to the harsh environmental conditions and the strict requirements for payload mass of the airborne platform, a structural design method is proposed for a good performance stability, lightweight and miniaturized laser expander system. In order to realize the lightweight and miniaturization design of the laser expander system, a miniaturized coaxial catadioptric defocus optical system is designed consisting of mirrors and lens. To ensure the stability and lightweight of the structure, the flexure and the main support structure which combined the thin-wall cylinder and truss are designed for the mirrors and lens. Finally, the engineering analysis of the system is carried out. The results show that the relative decenter and spacing between primary mirror and secondary mirror are 2.28μm and 5.92μm under normal working condition, respectively. The maximum surface shape error of the mirrors is 5.42nm. The first-order natural frequency of the system is 349.6Hz, and the maximum value of the root-mean-square of acceleration response under random vibration excitation occurs on the primary mirror, and the amplification factor is 7.1. It meets the mechanical performance requirements of airborne platform.