Principles of compensation of optical rays' rotation and multi-channel optical rotary connectors.

Abstract

This paper deals with some theoretical issues concerning the methods of compensation of optical beams' rotation as well as the ways to design multi-channel optical rotary connectors (ORCs) operating on the compensation principle. A theoretical foundation is given for a general method of compensation of optical beams' rotation that is based on stage-by-stage transformation of beam rotation angular velocity by using a set of optical transducers mounted sequentially along the light rays. The compensation process is described in general form by some mathematical equations. One of its solutions opens the possibility to make ORCs (based on the compensation principle of operation) without any geared mechanisms. They are much smaller than their analogues and provide high reliability and long-term operation at high rotation velocities. An example of the technical realization of an ORC based on two fiber-optic transducers of the original design is adduced. The construction of an ORC including a pioneering fiber-optic compensator (FOC) of high quality that can invert the beam rotation direction is described in detail. This FOC is made as a hollow fiber cylinder. The technological issues of manufacturing this compensator are briefly considered. Besides, the ORC construction with a compensator based on a triangular prism and two light guide bundles to transfer the images is described and analyzed theoretically. These bundles are optically coupled by one butt via the above prism, while their other butts are mounted along the rotation axis. An ORC facility with this compensator can be successfully used to transfer analog signals since it has potentially low rotational oscillations of optical signal amplitude at a level of several percent.