Dual-clad polarization-preserving optical fiber
AssigneeVerrillon, Inc.
InventorAbdelouahed Soufiane
Life of this patent
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Abstract
A polarization-preserving optical fiber with a high pump-radiation absorption efficiency including a core, a primary cladding surrounding the core, stress members disposed within the primary cladding, and a secondary cladding surrounding the core, primary cladding and stress members. The stress members and the primary cladding have different thermal responses, thereby inducing birefringence within the fiber. The cladding and stress members cooperate to direct light, propagating through the fiber, into the core.
Claims13
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.
A method of maintaining polarization and improving pump-energy efficiency within an optical fiber comprising the steps of:
- providing an optical fiber comprising a lasing core, a non-circular primary cladding, a secondary cladding, and a pair of stress members disposed within said primary cladding on opposite sides of said core and having a different thermal response than said primary cladding, said stress members causing birefringence within said primary cladding;
- and
- pumping light radially into said optical fiber, whereby said birefringence maintains a polarization of light propagating through said core, and said non-circular cladding directs said pumped light at said core as said light propagates through said optical fiber.
A method of maintaining polarization and increasing pump-energy efficiency within an optical fiber comprising the steps of:
- providing an optical fiber comprised of a core for carrying radiation, said core having a refractive index nc, a primary cladding surrounding said core having a refractive index npc, a secondary cladding surrounding said primary cladding having a refractive index nsc, and a pair of stress members within said primary cladding and disposed on opposite sides of said core, said stress members having a refractive index nsm, wherein (i) nc>npc>nsc and npc>nsm, (ii) said stress members and said primary cladding have different coefficients of thermal expansion thereby creating birefringence within said fiber, (iii) said stress members each have a flat surface facing said core, said stress-member flat surfaces being opposed to each other, and (iv) said primary cladding has a pair of opposed flat surfaces substantially perpendicular to said stress-member flat surfaces;
- pumping light radially into said optical fiber, whereby said birefringence maintains a polarization of light propagating through said core, and said primary cladding and said stress members direct said pumped light at said core as said light propagates through said optical fiber.
Dependencies are inferred from the claim text.