Vol. 31, Issue 2, pp. 479-487 (2001)

Abstract

A homodyne chopper for weak optical signal detection meant for monochromators is described. The software used is also discussed. Some design problems are mentioned, including the selection of operating frequency, optimisation of noise, and the choice of diaphragm shape. The measurement errors are also analysed. It follows that monochromator errors and photodetector sensitivity errors play a main role.