Suppression of Backscatter and Stray Reflection Induced Phase Noise in Michelson Interferometers.
Patent Application, filed 30 Apr 93,
DEPARTMENT OF THE NAVY WASHINGTON DC
Pagination or Media Count:
An optical system, including a reflectometric interferometer such as of the Michelson type, and method of reducing phase noise in such systems uses an uni-directional optical isolator in at least one of two optical links, such as optical fibers, to prevent propagation of backscattered radiation or radiation which may be backscattered in respective ones of the two optical links in order to limit the introduction of phase noise when the optical lengths andor illumination coherence length is made long. The uni-directional isolation is preferably done with polarization independent isolators comprising a Faraday rotator between two prisms. If the uni-directional isolators are placed adjacent the interferometer, the length of optical leads or links to and from the interferometer can be increased up to several kilometers in length without any significant increase in phase noise over the noise levels present in the interferometer alone.
- Fiber Optics and Integrated Optics