Abstract: A method of forming a linear polarization-maintaining optical fiber for use in an amplifier, the method comprising the steps of: providing a rare-earth-doped non-polarization-maintaining optical fiber having one or more cladding layers and having a random birefringence; providing a mandrel having a selected diameter; coiling said non-polarization-maintaining optical fiber under a selected tension around said mandrel to induce a linear birefringence greater than said random birefringence in said non-polarization-maintaining optical fiber thereby forming a polarization-maintaining optical fiber; wherein said mandrel diameter is chosen to avoid significant bend loss; wherein said rare-earth dopant is selected from the group consisting Nd3+, Yb3+, Pr3+, Ho3+, Er3+, Sm3+ and Tm3+; wherein said mandrel diameter is selected to be from about 0.1 cm to about 10 cm; and wherein said tension is chosen to avoid undesirable weakening of said non-polarization-maintaining fiber.

Abstract: An optical fiber includes a core doped with a preselected gain material, an inner cladding disposed about the core, an outer cladding, disposed about the inner cladding, that has a section removed to expose a portion of the inner cladding, a notch disposed in the exposed portion of the inner cladding, and a mirror disposed within the notch that includes a high reflectivity surface oriented so as to reflect light launched into the mirror from an outside source into the fiber. The mirror, e.g. a right-angle trihedron, has a high reflectivity (HR) coating on one face, is inserted into the notch, and affixed thereto with an adhesive such as an optical cement. Pump light, e.g. from a laser diode, is launched through a face of the mirror that is antireflection (AR) coated or sufficiently transparent to the light frequency, and after reflecting off the HR face exits through a third face and into the fiber.

Abstract: An optical fiber includes a core doped with a preselected gain material, an inner cladding disposed about the core, an outer cladding, disposed about the inner cladding, that has a section removed to expose a portion of the inner cladding, a notch disposed in the exposed portion of the inner cladding, and a mirror disposed within the notch that includes a high reflectivity surface oriented so as to reflect light launched into the mirror from an outside source into the fiber. The mirror, e.g. a right-angle trihedron, has a high reflectivity (HR) coating on one face, is inserted into the notch, and affixed thereto with an adhesive such as an optical cement. Pump light, e.g. from a laser diode, is launched through a face of the mirror that is antireflection (AR) coated or sufficiently transparent to the light frequency, and after reflecting off the HR face exits through a third face and into the fiber.

Abstract: A method of forming a linear polarization-maintaining optical fiber for use in an amplifier, the method comprising the steps of: