Laser radar with reference beam storage.

摘要

In a laser radar system, in which pulses from a laser 1 are focused by a telescope 6 onto a target, the back-scattered radiation being deflected by polarising beam splitter 4 onto a detector 2 in conjunction with a reference beam, the reference beam is produced from pulses derived from the pulse laser 1 by means of the beam splitter 3, the pulses making repeated journeys around a cavity 10 and a proportion of the pulse being emitted each time so that each pulse produces a multiplicity of output pulses to form the reference beam, thereby avoiding the need for a separate laser for the reference beam. <IMAGE>