Interferometric Optical Synchro for Alignment Transfer
Abstract
Two 50 nanoradian resolution angle transducers were built employing laser interferometric techniques. Each encoder was provided with a reference or zero marker which employed a white light Michelson interferometer. The encoders were operated and the performance of one was evaluated in terms of the performance of the other to evaluate the suitability of the encoders for use in an optical synchro system for alignment transfer. The specified angular resolution of 100 nanorad has been met with a performance of .43 nanorad resolution per root/Hz (10.5 nanorad at 600 Hz). The specification that requires one encoder to track the other within 100 nrad has been met by demonstrating that the second encoder will return to the zero reference position of the first encoder with 16 nrad (rms)/96 nrad (3 sigma). The encoders have been built as a self-contained device and is as much transportable. The implementation of the optical design is robust and we conclude that the encoder design is ready to be incorporated in a next higher level system, such as a combination of a reference platform/remote, slaved mirror. Keywords: Angle encoder; Frequency laser; Phase meter; Nanoradian resolution; Michelson interferometer; Zero mark generation; Reflective grating.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 09, 1989
- Accession Number
- ADA205089
Entities
People
- Herman Deweerd