VORRICHTUNG ZUM FESTSTELLEN EINES WINKELFEHLERS.

摘要

A first polarisation converter has a first set of a first ninety degrees phase difference plate (4) and a first 180 degrees phase difference plate (5) coupled together. The phase shift planes of the plates are controllable for adjusting polarisation planes of fundamental mode components which pass the higher mode detectors (2,3). The higher mode components are combined in a circuit (33) so that these components are in orthogonal relations. In a second polarisation converter, with phase difference plates (34,35), the second 180 degrees phase difference plate (35) precedes the ninety degrees phase difference plate (34) and its phase shift plane is controlled to maintain an angle of set angle of the first 180 degrees phase difference plate (5). The second ninety degrees phase difference plate (34) has its phase shift plane set at forty five degrees.