Dimensional stability of mirror materials for opto-mechanical reference system

Sensors, IR beams and lasers used in many opto-mechanical systems have stringent alignment retention requirements for use over an extended temperature range. Thermal effects are the primary cause for alignment drift during operation. Thermal expansion and contraction of materials can result in dimensional instability of mirror surfaces. This paper focuses on the importance of dimensional stability of mirror materials in alignment retention of the devised opto-mechanical reference system and addresses the cause of thermal instabilities which determine its functional accuracy. This is clearly shown by the agreement between the measurement results of dynamically varying form error of the mirror surface with temperature and the theoretical estimations. The test equipments and methods to validate the alignment stability of the opto-mechanical reference system are also presented.