Patent ID: 6118910
Filing Date: 2000-09-12
Classification: G02B,G02F

Abstract:
A method of assembling an optical device for selectively coupling optical signals among a unidirectional input port, a unidirectional output port and a bidirectional port comprising steps of:securing input and output optical fibers in a fixed generally parallel relationship;forming a stack of polarization-manipulating elements such that said stack includes input and output ports on a forward side of said stack and a bidirectional port on a rearward side opposite to said forward side, including positioning a controllable multi-state element within said stack such that an input beam from said input port is optically coupled to said bidirectional port when said controllable multi-state element is in a first state and such that an input beam from said output port is optically coupled to said bidirectional port when said multi-state controllable element is in a second state;directing light from said forward side of said stack toward said rearward side and selectively switching said controllable multi-state element to detect whether said bidirectional port is optically coupled to said input port and optically isolated from said output port when said controllable multi-state element is in said first state and to detect whether said bidirectional port is optically isolated from said input port and optically coupled to said output port when said controllable multi-state element is in said second state; andupon detecting that said selective optical couplings from said input and output ports to said bidirectional port exist, optically aligning a bidirectional optical fiber on said rearward side of said stack with a selected one of said input and output optical fibers on said forward side, wherein said step of directing said light and said step of optically aligning said bidirectional optical fiber are achieved without directing light from said stack to said input and output ports.