Abstract: A position measurement device includes a light source, a reflector coupled to a test object, a light detector between the light source and reflector, and a controller to measure a position of the test object based on an interference pattern generated by a reference beam and a measurement beam output from the light detector. The controller also controls a temperature of the light detector by generating signals for a heat exchanger having a Peltier region coupled to the light detector. The signals including a first signal to cause the heat exchanger to remove heat from the light receiver and a second signal to cause the heat exchanger to apply heat to the light receiver.