Abstract: A fiber includes a core and cladding, both of which may have temperature dependent indices of refraction. The materials and size of the core and cladding may be selected such that as the temperature of the core and/or cladding is heated above room temperature, the fiber transitions from supporting multimode optical waveguiding to supporting single mode waveguiding.

Abstract: Disclosed is an optical fiber formed from a preform that includes a clad component and a core component. The core component includes one or more precursor core materials. The precursor core materials and the clad materials are selected such that that the photoelastic constants of at least one precursor core material and the clad material are of opposite sign resulting in a final glass optical fiber of tailored Brillouin performance. The clad material may include an oxide glass having a positive photoelastic constant and the core component may include a precursor core material that has a negative photoelastic constant. During formation, the precursor core material can melt and interact with clad material that precipitates into the core to form a glass of at least one tailored Brillouin property, such as very low Brillouin gain.

Abstract: Disclosed is an optical fiber formed from a preform that includes a clad component and a core component. The core component includes one or more precursor core materials. The precursor core materials and the clad materials are selected such that that the photoelastic constants of at least one precursor core material and the clad material are of opposite sign resulting in a final glass optical fiber of tailored Brillouin performance. The clad material may include an oxide glass having a positive photoelastic constant and the core component may include a precursor core material that has a negative photoelastic constant. During formation, the precursor core material can melt and interact with clad material that precipitates into the core to form a glass of at least one tailored Brillouin property, such as very low Brillouin gain.

Abstract: A narrow linewidth injection-seeded Q-switched fiber ring laser based on a low-SBS optical fiber. High peak powers are achieved through the use of a single-clad erbium doped fiber with an acoustic waveguide. 12.5 ?J per pulse (250 ns pulse width) is achieved before a weakened form of stimulated Brillouin scattering appears. This laser has the potential to scale to very high power in a low-SBS dual clad fiber.

Abstract: An apparatus in one example has: a fiber having a representative refractive index profile, the refractive index profile having at least a core and a pedestal; and the fiber having a modal index in the core that is greater than a modal index of the pedestal at a predetermined signal wavelength. The fiber may also have a cladding, and may have a significantly increased index of refraction over a cladding material of the cladding to reduce effects of Stimulated Raman Scattering.