Deflection Multiplier for Reflecting Galvanometers

Abstract

A very simple multiple reflection system is described by which the effective sensitivity of a reflecting galvanometer can be increased by a factor of five or more without increasing the mirror to scale distance. The full width of the galvanometer mirror is used for each reflection, so that with a good quality mirror there is little reduction in the sharpness of the hairline image and only moderate reduction in the brightness of the spot. Use of a 2‐m path distance and four or five reflections makes it possible to extend the useful sensitivity of a sensitive galvanometer close to the limit set by Brownian movement. The principle of this amplifying system can be applied directly to most forms of optical lever.