Patent ID: 8434330
Filing Date: 2013-05-07
Classification: C03B

Abstract:
1. A method for fabricating a birefringent optical fiber, comprising: (a) fabricating a preform rod having a longitudinal axis, an outer peripheral surface, and a selected refractive index variation; (b) cutting at least one longitudinal groove into the preform rod through its outer peripheral surface; (c) loading a respective birefringence-inducing stress element into the at least one longitudinal groove, wherein the respective stress element has a cross sectional area that is substantially equal to that of the at least one longitudinal groove, and wherein the respective birefringence-inducing stress element and the at least one longitudinal groove are shaped, such that when the respective birefringence-inducing stress element is loaded into the at least one longitudinal groove, a portion of the stress element protrudes outside of the outer peripheral surface of the preform rod; (d) creating a preform assembly by positioning the loaded preform rod within an overcladding tube; and (e) drawing the preform assembly into optical fiber, wherein step (e) includes collapsing the overcladding tube around the preform rod and the at least one stress element loaded therein, such that an inner surface of the overcladding tube presses against the protruding portion of the at least one stress element so as to cause the stress element to be deformed and molded into the at least one longitudinal groove.