Analysis and Design of a New Phase-Modulated Michelson Interferometer.
Abstract
A new interferometer signal processing system has been designed, analyzed, constructed, and tested. It is based on phase modulation of the interferometer followed electronically by quadrature mixing and frequency-modulated (FM)-type detection. As a result, the system is entirely independent of direct current (dc) or polarization effects, and only one photodetector is required to provide directional information. The output is digital and analog. The range of the unit with two 8-bit counters is presently + or - 64 lambda; however, more counters could be combined to provide a total delta L to the beam coherence length. The unit will detect signals to 30 kHz. Resolution through fringe interpolation is possible to + or - lambda/95 at present, which can be improved with electronic modifications. Phase sensitivity is much greater, with about 3-microvolt signal per angstrom of length change. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 18, 1981
- Accession Number
- ADA112238
Entities
People
- E. G. Wolff
- R. C. Savedra
- S. A. Eselun
Organizations
- The Aerospace Corporation