Abstract: An HOM-based optical fiber amplifier is selectively doped within its core region to minimize the presence of dopants in those portions of the core where the unwanted lower-order modes (particularly, the fundamental mode) of the signal reside. The reduction (elimination) of the gain medium from these portions of the core minimizes (perhaps to the point of elimination) limits the amount of amplification impressed upon the backward-propagating Stokes wave. This minimization of amplification will, in turn, lead to a reduction in the growth of the Stokes power that is generated by the Brillouin gain, which results in increasing the amount of power present in the desired, forward-propagating HOM amplified optical signal output.

Abstract: The present disclosure is directed to removing unabsorbed cladding light in high-power optical systems. Some embodiments comprise a glass block with a refractive index that is greater than a refractive index of a fiber cladding, and a metal housing that is located external to the glass block. The glass block and the metal housing, in combination, removes excess light.

Abstract: An HOM-based optical fiber amplifier is selectively doped within its core region to minimize the presence of dopants in those portions of the core where the unwanted lower-order modes (particularly, the fundamental mode) of the signal reside. The reduction (elimination) of the gain medium from these portions of the core minimizes (perhaps to the point of elimination) limits the amount of amplification impressed upon the backward-propagating Stokes wave. This minimization of amplification will, in turn, lead to a reduction in the growth of the Stokes power that is generated by the Brillouin gain, which results in increasing the amount of power present in the desired, forward-propagating HOM amplified optical signal output.

Abstract: An HOM-based optical fiber amplifier is selectively doped within its core region to minimize the presence of dopants in those portions of the core where the unwanted lower-order modes (particularly, the fundamental mode) of the signal reside. The reduction (elimination) of the gain medium from these portions of the core minimizes (perhaps to the point of elimination) limits the amount of amplification impressed upon the backward-propagating Stokes wave. This minimization of amplification will, in turn, lead to a reduction in the growth of the Stokes power that is generated by the Brillouin gain, which results in increasing the amount of power present in the desired, forward-propagating HOM amplified optical signal output.

Abstract: Embodiments of the present invention are generally related to a high-power liquid-cooled pump and signal combiner and methods thereof for fiber optic applications. More specifically, embodiments of the present invention relate to a pump and signal combiner capable of conveying several kilowatts of pump laser power for kilowatt class rare-earth doped fiber amplifiers without suffering thermal damage. In one embodiment of the present invention, a high-power, heat dissipating optical fiber device comprises a section of optical fiber configured to propagate light, a cooling chamber, substantially encapsulating the optical fiber, and a fluid within the cooling chamber having a refractive index selected to control the interaction and propagation of the light in the fluid.

Abstract: Embodiments of the present invention are generally related to a high-power liquid-cooled pump and signal combiner and methods thereof for fiber optic applications. More specifically, embodiments of the present invention relate to a pump and signal combiner capable of conveying several kilowatts of pump laser power for kilowatt class rare-earth doped fiber amplifiers without suffering thermal damage. In one embodiment of the present invention, a high-power, heat dissipating optical fiber device comprises a section of optical fiber configured to propagate light, a cooling chamber, substantially encapsulating the optical fiber, and a fluid within the cooling chamber having a refractive index selected to control the interaction and propagation of the light in the fluid.

Abstract: An HOM-based optical fiber amplifier is selectively doped within its core region to minimize the presence of dopants in those portions of the core where the unwanted lower-order modes (particularly, the fundamental mode) of the signal reside. The reduction (elimination) of the gain medium from these portions of the core minimizes (perhaps to the point of elimination) limits the amount of amplification impressed upon the backward-propagating Stokes wave. This minimization of amplification will, in turn, lead to a reduction in the growth of the Stokes power that is generated by the Brillouin gain, which results in increasing the amount of power present in the desired, forward-propagating HOM amplified optical signal output.

Abstract: The present disclosure is directed to removing unabsorbed cladding light in high-power optical systems. Some embodiments comprise a glass block with a refractive index that is greater than a refractive index of a fiber cladding, and a metal housing that is located external to the glass block. The glass block and the metal housing, in combination, removes excess light.

Abstract: The present disclosure provides an approach to more efficiently amplify signals by matching either the gain materials or the pump profile with the signal profile for a higher-order mode (HOM) signal. By doing so, more efficient energy extraction is achieved.

Abstract: A fiber amplifier suitable for high power, narrow linewidth applications exhibits suppression of stimulated Brillouin scattering (SBS) by segmenting the fiber amplifier into separate portions that exhibit different Brillouin center frequencies. By changing the center frequencies in adjoining segments of the fiber amplifier, the backward-propagating Stokes signal is essentially blocked, and SBS is suppressed. In a preferred embodiment the segmentation is added to the terminating portion of the fiber amplifier. Various techniques, including temperature modifications, can be used to impart the desired center frequency shift.

Abstract: The present disclosure provides an approach to more efficiently amplify signals by matching either the gain materials or the pump profile with the signal profile for a higher-order mode (HOM) signal. By doing so, more efficient energy extraction is achieved.

Abstract: A fiber amplifier suitable for high power, narrow linewidth applications exhibits suppression of stimulated Brillouin scattering (SBS) by segmenting the fiber amplifier into separate portions that exhibit different Brillouin center frequencies. By changing the center frequencies in adjoining segments of the fiber amplifier, the backward-propagating Stokes signal is essentially blocked, and SBS is suppressed. In a preferred embodiment the segmentation is added to the terminating portion of the fiber amplifier. Various techniques, including temperature modifications, can be used to impart the desired center frequency shift.

Abstract: The specification describes a distributed Raman amplifier with multiple pump sources for wide band amplification of wavelength division multiplexed (WDM) signals. It was recognized that using multiple pump sources introduces non-linear effects, such as four wave mixing (FWM). These effects are reduced by multiplexing the pump wavelengths in the multiple pump source. It was also recognized that not all of the pump wavelengths over the wavelength spectrum of the pumps contributes to FWM. Thus fewer than all of the pump wavelengths require multiplexing to eliminate FWM in the multiple wavelength pump source. Various approaches are described to ensure that the pump wavelengths do not interact in FWM in the transmission span. The selected individual pump wavelengths may be either time division multiplexed, or frequency modulated.

Abstract: The specification describes a distributed Raman amplifier with multiple pump sources for wide band amplification of wavelength division multiplexed (WDM) signals. It was recognized that using multiple pump sources introduces non-linear effects, such as four wave mixing (FWM). These effects are reduced by multiplexing the pump wavelengths in the multiple pump source. It was also recognized that not all of the pump wavelengths over the wavelength spectrum of the pumps contributes to FWM. Thus fewer than all of the pump wavelengths require multiplexing to eliminate FWM in the multiple wavelength pump source. Various approaches are described to ensure that the pump wavelengths do not interact in FWM in the transmission span. The selected individual pump wavelengths may be either time division multiplexed, or frequency modulated.