Research on Large Aperture Multi-Angle Multi-Surface Mirror Process Technology

摘要

Light weighted multi-angle multi-surface mirror is made of glass-ceramic, with the structural characteristic of multi-cavity thin wall, high precision of surface figure and angle between surfaces, has very different processing technology with traditional solid mirror. Based on the 460mm×434mm×80mm multi-angle multi-surface mirror, glass combination manufacture method and relevant interferometry of angle measurement was designed. The process technology was studied, then the consistency of angle between surfaces and the influence on multi-cavity thin wall deformation of lateral surface and material of polishing pad on the surface figure processing were controlled. The model between the variation of angle and load was established, from which the hysteresis of angle variation was analyzed, then the prototype workpiece was finished. The difficult problem on synchronically controlling the surface angles and surface figure of the mirror, which has high center of gravity and multi-cavity thin wall, was solved. The lateral surface figure was controlled below λ/6 (PV, λ=632.8nm), and the perpendicularity of lateral surfaces were controlled below 5".