System and method for direct measurement of alignment error in a fiber coupler
First Claim
1. An optical switch for use with an incident light beam, comprising first and second optical fibers, a beam positioner for selectively coupling said incident light beam into one of said first and second optical fibers, a quadrant detector for sensing at least a portion of a reflected light beam reflected back out of the one of said first and second optical fibers so as to determine an offset signal corresponding to an offset position between said incident light beam and said reflected light beam and a controller coupled to said quadrant detector and said beam positioner for moving said beam positioner so as to minimize said offset position between said incident light beam and said reflected light beam and thereby increase the coupling efficiency into the one of said first and second optical fibers.
7 Assignments
0 Petitions
Accused Products
Abstract
A system and method for directly measuring the alignment error in a fiber-optic coupler is disclosed. In one embodiment, an optical switch utilizes a beam deflection mirror. When the beam deflection mirror directs an incident light beam to a particular fiber, the incident light beam may enter the fiber at a location offset from the center of the fiber. When the incident beam is reflected at the opposite end of the fiber, the beam returns and exits the fiber exactly at the center of the fiber. The difference between the entry and exit points results in a return beam path different than the incident beam path. This different return beam path may be used to impinge upon a quadrant detector, whose anode currents may then contain a direct measurement of the distance between the entry and exit points on the fiber.
-
Citations
39 Claims
- 1. An optical switch for use with an incident light beam, comprising first and second optical fibers, a beam positioner for selectively coupling said incident light beam into one of said first and second optical fibers, a quadrant detector for sensing at least a portion of a reflected light beam reflected back out of the one of said first and second optical fibers so as to determine an offset signal corresponding to an offset position between said incident light beam and said reflected light beam and a controller coupled to said quadrant detector and said beam positioner for moving said beam positioner so as to minimize said offset position between said incident light beam and said reflected light beam and thereby increase the coupling efficiency into the one of said first and second optical fibers.
- 17. A system for measurement of an alignment error between an incident light beam and an optical fiber, comprising an incident beam path configured to allow said incident light beam to impinge upon a fiber terminator of said optical fiber, a return beam path extending from said fiber terminator of said optical fiber and configured to return light from said incident light beam and a quadrant detector configured to measure an offset between said return beam path and said incident beam path, said fiber terminator being located within a fiber-optic switch of an optical disk drive.
- 19. A system for measurement of an alignment error between an incident light beam and an optical fiber, comprising an incident beam path configured to allow said incident light beam to impinge upon a fiber terminator of said optical fiber, a return beam path extending from said fiber terminator of said optical fiber and configured to return light from said incident light beam and a quadrant detector configured to measure an offset between said return beam path and said incident beam path, said fiber terminator being located within a fiber-optic switch and a current from said quadrant detector driving a servo-control circuit.
- 22. A method of coupling an incident light beam into one of first and second optical fibers using an optical switch having a quadrant detector, comprising the steps of selectively directing said incident light beam along an incident beam path so as to couple said incident light beam into said one of first and second optical fibers, sensing with said quadrant detector at least a portion of a reflected light beam reflected back out of said one of first and second optical fibers so as to determine an offset signal corresponding to an offset position between said reflected light beam and said incident light beam and moving said incident light beam so as to minimize said offset position.
Specification