摘要:
Adverse hydrogen aging limitations in multiply-doped optical fibers are overcome by passivating these optical fibers using a deuterium passivation process. This treatment essentially pre-reacts the glass with deuterium so that the most active glass sites are no longer available to react with hydrogen in service. Optical fibers of main interest are doped with mixtures of germanium and phosphorus. Optimum passivating process conditions are described.
摘要:
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.
摘要:
Disclosed are multi-stage optical amplifiers that propagate higher-order mode (HOM) signals. One embodiment, among others, comprises a first segment of optical fiber in which a first HOM signal propagates, a second segment of optical fiber in which a second HOM signal propagates, and a mode converter that converts the first HOM signal into the second HOM signal.
摘要:
The specification describes optical fiber gain devices, such as lasers and amplifiers, wherein losses due to a large step transition between an input section and a gain section are reduced by inserting an adiabatic transformer between the input section and the gain section. In the preferred case the adiabatic transformer comprises a GRadient INdex (GRIN) lens. The lens serves as an adiabatic beam expander (reducer) to controllably increase (reduce) the modefield of the beam as it travels through the step transition.
摘要:
Multistage Er-doped fiber amplifiers (EDFAs) advantageously use high numerical aperture (NA) fiber in the input stage, and low NA fiber in the output stage. The former typically is greater than 0.25, and the latter is less than 0.20. Such amplifiers can have high gain and low noise figure.
摘要:
A passive optical attenuating device comprises an optical waveguide adapted to receive optical radiation and absorb, along its length, at least 0.2 dB/m of the optical radiation. The waveguide section may be coupled to a low-loss optical fiber so as to receive an optical signal to be attenuated therefrom. In accordance with one aspect of the invention, at least one region of the waveguide is doped with a transition metal to achieve a pre-selected absorptivity per unit length so that a controlled degree of attenuation can be achieved.
摘要:
The present invention relates to a method of mitigating gain peaking in a chain of fiber amplifiers by pumping the amplifiers at a predetermined wavelength to produce gain over a specified wavelength range.
摘要:
A method of creating optical fiber to exhibit predetermined length-dependent characteristics (e.g., chromatic dispersion, polarization mode dispersion, cutoff wavelength, birefringence) includes the steps of: characterizing the fiber's selected characteristic(s) as a function of length; and performing a “treatment” which modifies the refractive index over the given length to adjust the defined parameter to fall within a defined tolerance window. These steps may be repeated one or more times until the measure of the parameter falls with the defined tolerance limits. The treatment process may include, for example, a low energy actinic radiation exposure, anneal, mechanical strain, DC voltage, plasma application, etc. Indeed, if the treatment process is repeated, a different technique may be used to adjust the refractive index (“different” processes include, for example, modifying the strength/time of a UV exposure, temperatures for annealing, etc.).
摘要:
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.
摘要:
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.