Patent ID: 6608956
Filing Date: 2003-08-19
Classification: G02B,H01S

Abstract:
A fiber adapted to maintain polarization with improved pump-energy efficiency, said fiber comprising:a. a core for carrying radiation, said core having a refractive index nc; b. a primary cladding surrounding said core and having a refractive index npc; c. a secondary cladding surrounding said primary cladding and having a refractive index nsc; d. within said primary cladding, a pair of stress members disposed on opposite sides of said core and having a refractive index nsm, wherein: e. nc>npc>nsc; f. npc>nsm; g. said stress members and said primary cladding have different coefficients of thermal expansion, thereby creating birefringence in said fiber; h. said stress members each have a flat surface facing said core, said stress-member flat surfaces being opposed to each other; and i. said primary cladding has a pair of opposed flat surfaces substantially perpendicular to said stress-member flat surfaces, said stress-member flat surfaces and said primary-cladding flat surfaces cooperating to reflect light into said core as it propagates through said fiber.