Abstract: An optical circuit breaker includes a main optical transmission path including an optical coupler, a delay line and a protection device, and a parallel protection path configured to receive a tapped portion of a signal provided to the main optical transmission path and generate a reference signal based on the tapped portion. The protection device may be configured to be triggered to prevent an overpower condition from passing through the optical circuit breaker responsive to the reference signal exceeding a user selectable threshold. The delay line may be configured to have a longer delay than a time it takes for the protection device to be triggered via the parallel protection path.

Abstract: Example apparatuses and methods are provided that improve laser performance or decrease the frequency or severity of the occurrence of Stimulated Brillouin scattering. One example is a laser device that may include a seed laser configured to generate an optical output, a pattern generator configured to generate a modulation pattern, and a phase modulator configured to apply a modulation scheme to the optical output based on the modulation pattern. The modulation pattern may include a digital sequence and the modulation pattern may be applied to modulate a phase or an amplitude of the optical output.

Abstract: A detection system includes a photonic module, a radio frequency (RF) module and processing circuitry. The photonic module may be configured to generate an optical tone for modulation in an optical domain prior to conversion to the RF domain. The RF module may be configured to interface with the photonic module to receive a transmission signal converted from the optical domain. The processing circuitry may be configured to interface with the photonic module and RF module to enable an operator to control of the photonic module and the RF module at least with respect to selectively determining a carrier frequency of the optical tone and a modulation technique to be employed with respect to the transmission signal converted from the optical domain.

Abstract: An optical circuit breaker includes a main optical transmission path including an optical coupler, a delay line and a protection device, and a parallel protection path configured to receive a tapped portion of a signal provided to the main optical transmission path and generate a reference signal based on the tapped portion. The protection device may be configured to be triggered to prevent an overpower condition from passing through the optical circuit breaker responsive to the reference signal exceeding a user selectable threshold. The delay line may be configured to have a longer delay than a time it takes for the protection device to be triggered via the parallel protection path.

Abstract: A laser device includes a seed laser, a polarizer, a pseudorandom bit sequence (PRBS) pattern generator, and a phase modulator. The polarizer may be optically coupled to receive an output of the seed laser and may generate a polarization filtered output. The PRBS pattern generator may be configured to generate a PRBS pattern. The phase modulator may be configured to apply a PRBS modulation scheme to the polarization filtered output based on the PRBS pattern. The PRBS pattern may be generated to have a length above a first threshold for avoiding an occurrence of backward propagation being in phase with forward propagation in an active fiber receiving an output of the phase modulator when the pattern repeats and below a second threshold for phase mismatch in the active fiber.

Abstract: A universal optical receiver may include an optical channel monitor configured to acquire spectral data for an optical signal on at least one selected optical channel, a tunable local oscillator configured to be tuned to a center frequency of the optical signal on the at least one selected optical channel, a storage device configured to store data associated with the optical signal responsive to acquisition of the spectral data and tuning of the tunable local oscillator, and processing circuitry configured to execute an algorithm that employs a plurality of binary distinctions based on physical characteristics of the optical signal and employs at least one calculation of figure of merit associated with a series of parameter values of the optical signal to identify a format of the optical signal.

Abstract: A laser device includes a seed laser, a polarizer, a pseudorandom bit sequence (PRBS) pattern generator, and a phase modulator. The polarizer may be optically coupled to receive an output of the seed laser and may generate a polarization filtered output. The PRBS pattern generator may be configured to generate a PRBS pattern. The phase modulator may be configured to apply a PRBS modulation scheme to the polarization filtered output based on the PRBS pattern. The PRBS pattern may be generated to have a length above a first threshold for avoiding an occurrence of backward propagation being in phase with forward propagation in an active fiber receiving an output of the phase modulator when the pattern repeats and below a second threshold for phase mismatch in the active fiber.

Abstract: A universal optical receiver may include an optical channel monitor configured to acquire spectral data for an optical signal on at least one selected optical channel, a tunable local oscillator configured to be tuned to a center frequency of the optical signal on the at least one selected optical channel, a storage device configured to store data associated with the optical signal responsive to acquisition of the spectral data and tuning of the tunable local oscillator, and processing circuitry configured to execute an algorithm that employs a plurality of binary distinctions based on physical characteristics of the optical signal and employs at least one calculation of figure of merit associated with a series of parameter values of the optical signal to identify a format of the optical signal.

Abstract: A detection system includes a photonic module, a radio frequency (RF) module and processing circuitry. The photonic module may be configured to generate an optical tone for modulation in an optical domain prior to conversion to the RF domain. The RF module may be configured to interface with the photonic module to receive a transmission signal converted from the optical domain. The processing circuitry may be configured to interface with the photonic module and RF module to enable an operator to control of the photonic module and the RF module at least with respect to selectively determining a carrier frequency of the optical tone and a modulation technique to be employed with respect to the transmission signal converted from the optical domain.

Abstract: A device and method for reducing amplified Rayleigh backscatter at a Raman pump. A pump assembly for an optical amplifier includes a set of pump radiation sources for Raman pumping an optical transmission span. Each pump radiation source is adapted to produce radiation having a pump wavelength and a pump power. The optical transmission span is adapted to provide Raman amplification of an optical data signal when pumped by the set of pump radiation sources. At least one optical isolator is selectively located between at least one selected pump radiation source and the optical transmission span to reduce amplified Rayleigh backscatter at the pump wavelength of the selected pump radiation source from feeding back into the selected at least one pump radiation source.

Abstract: A system and method of providing a transmission span for a telecommunications link based on a remote Er3+-doped fiber amplification scheme is provided, where a transmission span comprises first through third segments each respectively comprising first-third optical fibers having first-third fiber lengths and first-third physical properties. The first and third segments are optically coupled to opposing ends of the second segment. At least one of the first and third physical properties is different from the second physical property, where the first segment provides low nonlinearity, the third segment provides distributed gain, and the second segment compensates for the dispersion of the first and third segments. The span also includes a fourth optical fiber that is doped with a non-zero concentration of Er3+, and is disposed at a location in the span for remote pumping to provide discrete amplification of the optical signal.

Abstract: A system and method of providing a transmission span for a telecommunications link based on a remote Er3+-doped fiber amplification scheme is provided, where a transmission span comprises first through third segments each respectively comprising first-third optical fibers having first-third fiber lengths and first-third physical properties. The first and third segments are optically coupled to opposing ends of the second segment. At least one of the first and third physical properties is different from the second physical property, where the first segment provides low nonlinearity, the third segment provides distributed gain, and the second segment compensates for the dispersion of the first and third segments. The span also includes a fourth optical fiber that is doped with a non-zero concentration of Er3+, and is disposed at a location in the span for remote pumping to provide discrete amplification of the optical signal.

Abstract: A modified silica glass composition for providing a reduction in the multiphonon quenching for a rare-earth dopant comprising: SiO2 in a host material; a rare-earth dopant; a first SiO2 modifier; and a second SiO2 modifier; such that said first modifier and said second modifier reduce multiphonon quenching of the rare-earth dopant contained therein.

Abstract: A system and method of providing a transmission span that compensates for signal attenuation, dispersion, and nonlinearity of an optical signal communicated between two line units of a transmission link includes dividing the transmission span into a plurality of fiber segments and selecting a particular fiber for each of the segments. The fiber selection and arrangement of fibers within the span can be selected in accordance with the nonlinearity, dispersion conditions, and distributed gain conditions of the constituent fibers. In a three segment map, the first segment can provide low non linearity, the third segment can provide distributed gain, and the second segment can compensate for the dispersion of the first and third segments. The span can be used, e.g., for distributed Raman amplification. The span can alternatively include a two segment map, a four segment map, or a map with additional segments.

Abstract: A system and method of providing a transmission span that compensates for signal attenuation, dispersion, and nonlinearity of an optical signal communicated between two line units of a transmission link includes dividing the transmission span into a plurality of fiber segments and selecting a particular fiber for each of the segments. The fiber selection and arrangement of fibers within the span can be selected in accordance with the nonlinearity, dispersion conditions, and distributed gain conditions of the constituent fibers. In a three segment map, the first segment can provide low non linearity, the third segment can provide distributed gain, and the second segment can compensate for the dispersion of the first and third segments. The span can be used, e.g., for distributed Raman amplification. The span can alternatively include a two segment map, a four segment map, or a map with additional segments.

Abstract: A method and apparatus for increasing the upper frequency range of an optical communication system, particularly one designed to communicate over, repeaterless, distances. A series of temporally interleaved optical solitons of different frequencies are generated, and transmitted and detected by wavelength division multiplexing. An adiabatic transmission line forms part of the transmission link, and serves to narrow the bandwidth of the pulses during propagation. As a result, one can generate the solitons with substantially overlapping spectra, thus increasing the rate at which they are produced, but, because of the narrowed spectra, still resolve them in frequency at the system's receiver.

Abstract: A modified silica glass composition for providing a reduction in the multiphonon quenching for a rare-earth dopant comprising:

Abstract: An optical receiver for receiving a signal from an optical fiber in a fiber-optic digital transmission system that includes a first low noise optical amplifier to amplify an input optical signal. The first low noise optical amplifier has an input 3 dB compression point lower than the desired system input sensitivity at a desired bit rate. A high power optical amplifier further amplifies the amplified optical signal, and has an automatic gain control for output signal leveling at a desired operation point of the transmission system. A high current photodetector converts the further amplified optical signal from the high power optical amplifier to an electrical signal that drives a retiming circuit without requiring further amplification of the electric signal.

Abstract: In accordance with one aspect of the invention, a ring laser configuration having a polarizer, and whose cavity loop has substantially no net dispersion, permitting mode locked pulsing of high intensity and large bandwidth. In accordance with another aspect of the invention, a system using this laser to interrogate a plurality of arrays of Bragg gratings by use of both time and wavelength division multiplexing, increasing the total number of interrogatable gratings. In accordance with a third aspect of the invention, a system for interrogating one or more fiber Bragg gratings separated from the optical source by a dispersive optical fiber. As such a grating distends responsive to some measurand, its reflection frequency changes, and the traversal time of the reflection over the dispersive fiber changes, permitting inference of the measurand.

Abstract: An optical method and apparatus particularly useful as an intensity modulation system, in which two phase modulators are placed in the loop of a Sagnac interferometer. Selective placement of the modulators, and the amplitude of any modulation signal input to the modulators, varies the bandwidth and frequency response of the system. In a preferred embodiment, the ratio of the optical distances of the modulators from interferometric midpoint, and the ratio of modulation signal amplitudes, is about 3:1, which serves to broaden and flatten the frequency response of the system.