Four-mode ring laser gyroscope - has reflecting mirror surfaces mounted on quartz block producing small incident angles

摘要

The reflecting surfaces for a four mode ring laser gyroscope are composed of several layers of dielectric material. coupling between modes is avoided by using a mirror configuration which allows small angles of incidence to be used. Reflecting mirror surfaces (24, 26, 28, 30) are mounted on chamfered surfaces (32, 34, 36, 38) of a quartz block (22). Passages (42, 44, 46, 48) are arranged to extend between the mirrors to allow passage of the laser beams. A quartz element (52) with longitudinal magnetisation is attached to the block to ensure multimode operation in the gyroscope.