Interferometer surface measurement device incorporates a controllable filter in either measurement or reference arm so that the intensity of interfering light can be optimized to improve measurement accuracy

摘要

Interferometer measurement device (10) has a measurement object (3.2), the surface of which is to be measured, in a measurement arm (3) and a reference surface (4.2) in a reference arm (4). An analysis branch comprises photoelectric receiver (5.2) and analysis unit (5.3). The reference arm and or the measurement arm contain a filter (4.3) that is electrically controlled by a control unit (5.4). The filter varies the intensity of transmitted light.