Abstract: An optical amplifier system comprises an optical gain medium receiving an input optical signal and outputting an amplified optical signal and a pump laser optically coupled to an input of the optical gain medium, wherein the pump laser emits a series of pulses to the optical gain medium, the pulses being emitted during coherence collapse operation of the pump laser, the time between pulses being shorter than an excited state lifetime of the optical gain medium.

Abstract: A method for manufacturing optical fiber with enhanced photosensitivity comprising the step of: forming a molten layer of glass and drawing a fiber from the molten layer of glass at a temperature of between about 1900° C. and 1995° C. Draw tension can be adjusted to attain the desired draw speed.

Abstract: An optically active waveguide laser (30) includes a multimode portion (126) for carrying more than one spatial mode at a predetermined wavelength chosen from a bandwidth including a pump wavelength (64) and the lasing wavelength (66). The multimode portion (126) has a first refractive index. A cladding portion (386) is proximate the multimode portion (126). A multimode grating (60, 56, or 62) is written on at least one section (26) of the multimode portion for reflecting the predetermined wavelength.

Abstract: A method for manufacturing an optical grating on a length of optical fiber having input and output ends. Guided light is conducted into the input end of the fiber and light reflected back from the output end is measured with an optical sensor. An optical grating is formed in the fiber between the input and output ends and guided light is conducted into the input end of the fiber and light reflected back from the grating is measured with an optical sensor. Measured light is compared to determine a percentage of guided light reflected back from the grating.

Abstract: The present invention provides photonic devices utilized in optical telecommunications. The photonic devices include photosensitive bulk glass bodies which contain Bragg gratings, particularly with the ultraviolet photosensitive bulk glass bodies directing optical telecommunications wavelength range bands. Preferably the ultraviolet photosensitive bulk glass bodies are batch meltable alkali boro-alumino-silicate bulk glass bodies. One embodiment of the invention relates to an optical element including a transparent photosensitive bulk glass having formed therein a non-waveguiding Bragg grating; and a optical element optical surface for manipulating light. Desirably, the photosensitive bulk glass has a 250 nm absorption less than 10 dB/cm.

Abstract: The present invention includes a method of making a preform for an enhanced photosensitive fiber comprising depositing successive layers of optical material the inside a tube using modified chemical vapor deposition, and collapsing the layers of optical material in a reducing atmosphere with a positive pressure. The present invention also includes a method of making an enhanced photosensitive fiber comprising making a preform using modified chemical vapor deposition wherein the preform is collapsed in a reducing atmosphere with a positive pressure and drawing the preform into a fiber.

Abstract: A fast, environmentally-stable fiber switch uses a Sagnac interferometer having an active fiber portion located asymmetrically in the loop of the interferometer. A pump pulse is applied to the interferometric loop and acts upon the active fiber portion to cause a change in its refractive index either by a thermal effect or by a non-thermal nonlinear effect. Because the active fiber portion is located asymmetrically in the loop, the change in refractive index of the active fiber portion is seen by the clockwise propagating light signal and the counterclockwise propagating light signal at different times, thus causing a temporary difference in the phase changes experienced by the two counterpropagating light signals.

Abstract: The invention provides a selectively absorbing optical fiber that is transparent at pump wavelengths, and highly absorbing at signal wavelengths. The selectively absorbing optical fiber includes selectively absorbing species, such as rare earth ions, in concentrations sufficient to provide the desired absorbance selectivity. The fiber is useful as a fiber pigtail for pump lasers in optical amplifiers, where it can reduce the effects of multi-path interference by absorbing stray light with wavelengths in the signal band.

Abstract: The present invention provides photonic devices utilized in optical telecommunications. The photonic devices include photosensitive bulk glass bodies which contain Bragg gratings, particularly with the ultraviolet photosensitive bulk glass bodies directing optical telecommunications wavelength range bands. Preferably the ultraviolet photosensitive bulk glass bodies are batch meltable alkali boro-alumino-silicate bulk glass bodies.

Abstract: An optically active waveguide laser (30) includes a multimode portion (126) for carrying more than one spatial mode at a predetermined wavelength chosen from a bandwidth including a pump wavelength (64) and the lasing wavelength (66). The multimode portion (126) has a first refractive index. A cladding portion (386) is proximate the multimode portion (126). A multimode grating (60, 56, or 62) is written on at least one section (26) of the multimode portion for reflecting the predetermined wavelength.

Abstract: The invention provides a selectively absorbing optical fiber that is transparent at pump wavelengths, and highly absorbing at signal wavelengths. The selectively absorbing optical fiber includes selectively absorbing species, such as rare earth ions, in concentrations sufficient to provide the desired absorbance selectivity. The fiber is useful as a fiber pigtail for pump lasers in optical amplifiers, where it can reduce the effects of multi-path interference by absorbing stray light with wavelengths in the signal band.

Abstract: A method for manufacturing optical fiber with enhanced photosensitivity comprising the step of: forming a molten layer of glass and drawing a fiber from the molten layer of glass at a temperature of between about 1900° C. and 1995° C. Draw tension can be adjusted to attain the desired draw speed.

Abstract: The present invention provides photonic devices utilized in optical telecommunications. The photonic devices include photosensitive bulk glass bodies which contain Bragg gratings, particularly with the ultraviolet photosensitive bulk glass bodies directing optical telecommunications wavelength range bands. Preferably the ultraviolet photosensitive bulk glass bodies are batch meltable alkali boro-alumino-silicate bulk glass bodies.

Abstract: A method for manufacturing an optical grating on a length of optical fiber having input and output ends. Guided light is conducted into the input end of the fiber and light reflected back from the output end is measured with an optical sensor. An optical grating is formed in the fiber between the input and output ends and guided light is conducted into the input end of the fiber and light reflected back from the grating is measured with an optical sensor. Measured light is compared to determine a percentage of guided light reflected back from the grating.

Abstract: The present invention includes a method of making a preform for an enhanced photosensitive fiber comprising depositing successive layers of optical material the inside a tube using modified chemical vapor deposition, and collapsing the layers of optical material in a reducing atmosphere with a positive pressure. The present invention also includes a method of making an enhanced photosensitive fiber comprising making a preform using modified chemical vapor deposition wherein the preform is collapsed in a reducing atmosphere with a positive pressure and drawing the preform into a fiber.

Abstract: A fast, environmentally-stable fiber switch uses a Sagnac interferometer having an active fiber portion located asymmetrically in the loop of the interferometer. A pump pulse is applied to the interferometric loop and acts upon the active fiber portion to cause a change in its refractive index either by a thermal effect or by a non-thermal nonlinear effect. Because the active fiber portion is located asymmetrically in the loop, the change in refractive index of the active fiber portion is seen by the clockwise propagating light signal and the counterclockwise propagating light signal at different times, thus causing a temporary difference in the phase changes experienced by the two counterpropagating light signals.

Abstract: A fast, environmentally-stable fiber switch uses a Sagnac interferometer having an active fiber portion located asymmetrically in the loop of the interferometer. A pump pulse is applied to the interferometric loop and acts upon the active fiber portion to cause a change in its refractive index either by a thermal effect or by a non-thermal nonlinear effect. Because the active fiber portion is located asymmetrically in the loop, the change in refractive index of the active fiber portion is seen by the clockwise propagating light signal and the counterclockwise propagating light signal at different times, thus causing a temporary difference in the phase changes experienced by the two counterpropagating light signals.

Abstract: The present invention provides photonic devices utilized in optical telecommunications. The photonic devices include photosensitive bulk glass bodies which contain Bragg gratings, particularly with the ultraviolet photosensitive bulk glass bodies directing optical telecommunications wavelength range bands. Preferably the ultraviolet photosensitive bulk glass bodies are batch meltable alkali boro-alumino-silicate bulk glass bodies.

Abstract: An optical fiber has two or more cores with respective faces on the fiber's ends. The faces are preferably oriented so that optical radiation can be coupled into or out of the individual cores, thereby permitting, for example, optical radiation from the various cores to be spatially resolved in the far field. The faces can be formed on the fiber by polishing the fiber at an angle with respect to the cores, i.e., with respect to the optical paths traversed by the optical radiation passing through the fiber.