Portable autocollimators using the laser diode and the position sensitive detector

We were able to simplify the structure of the autocollimators and enhance the performance by using one- and two-axis PSDs (position-sensitive detectors) which have spatial resolution of 0.1 and 2.5 μm, respectively, with little dependence on the spot size of incident beam and the visible laser diodes as the light source. Two kinds of portable autocollimators which can measure angles with resolutions 0.01^″ and 0.1^″, respectively, were made. They were calibrated by the reference angle generator which employed the laser interferometer. The characteristics of temporal stability were evaluated and the profile of a test surface was measured. © 1998 American Institute of Physics.