Abstract: An optical communications system initiates automatic power reduction by selecting a portion of a Raman optical pumping signal from optical signals propagating on an optical fiber span. A signal related to a magnitude of the selected portion of the Raman optical pumping signal is generated. Power of at least one of the optical data signals and the optical pumping signals propagating in the optical fiber span is reduced in response to the generated signal.

Abstract: An optical communications system includes a plurality of optical fiber spans. An optical loss of one of the plurality of optical fiber spans is different from an optical loss of another one of the plurality of optical fiber spans. At least one of the plurality of optical fiber spans includes an optical loss that is greater than or equal to 35 dB and at least one of the plurality of optical fiber spans includes an optical loss that is less than 30 dB. An optical amplification system includes at least one discrete optical amplifier, at least one distributed optical amplifier, and an optical loss element. The optical amplification system has spectral gain that compensates for substantially all losses experienced by the optical signals propagating in the plurality of optical fiber spans.

Abstract: An optical supervisory channel includes a transmit path that propagates optical supervisory signals to a high span loss optical fiber span having an optical loss that is greater than 35 dB. A wavelength division multiplexer adds the optical supervisory signals to the high span loss optical fiber span. A second wavelength division multiplexer extracts the optical supervisory signals from the high span loss optical fiber span. A receive path propagates the optical supervisory signals away from the high span loss optical fiber span. The optical supervisory channel also includes a means for reducing a bit error rate of the optical supervisory channel.

Abstract: In a stabilized laser system, a an output signal is to be generated having a desired central wavelength. At least one laser, which, while emitting light and having a preselected portion thereof fed back thereto, causes the output signal of the laser to be shifted in wavelength in a first direction which is spaced apart from the center wavelength of the fed back signal. A feedback generating arrangement processes a first portion of the output signal from each laser and generates a feedback signal having a spectral response peaking at a wavelength shifted in an opposite direction to the first direction generated by each laser. The feedback signal each laser to provide an output signal at the output of the stabilized laser system having a spectral response that peaks essentially at the desired wavelength.

Abstract: In a stabilized laser system, an output of a desired wavelength is generated. Each of a plurality of n lasers, which, while emitting light and having a preselected portion thereof fed back thereto, causes the fed back portion to be amplified and shifted in wavelength in a first direction which is spaced apart from the center wavelength of the feedback signal. A feedback stabilization arrangement is coupled to output ports of the plurality of n lasers for generating a feedback signal having a wavelength spectrum peaking at a wavelength shifted in an opposite direction to the first direction generated by the lasers in response to the feedback signal so as to provide an output signal at the output of the stabilized laser system having a wavelength spectrum that peaks essentially at the desired wavelength. A reflector is located at a predetermined signal round-trip time delay distance from the feedback stabilization arrangement.

Abstract: A basic reflector arrangement has first and second power splitters. Each power splitter has first to fourth ports where the first port of the first power splitter is coupled to a remote signal source for receiving signals therefrom and providing feedback signals thereto. Signals received at each of the first and fourth ports of each power splitter are combined and split into first and second portions for transmission via the second and third ports, respectively, and signals received at the second and third ports are combined and split into first and second portions for transmission via the first and fourth ports, respectively. The second port of the second power splitter is coupled to provide an output signal from the reflector arrangement, and the first, third, and fourth ports thereof are coupled to the second, third, and fourth ports, respectively, of the first power splitter.

Abstract: A multi-source optical module is described that includes an optical circuit positioned on a base. The optical circuit includes a first and a second optical input. A first and a second optical source are positioned on the base relative to the optical circuit. A first lens is positioned between an output of the first optical source and a first input of the optical circuit. A second lens is positioned between an output of the second optical source and a second input of the optical circuit. At least one of the first and the second lenses are positionable so that the output of a respective one of the first and second optical sources and a respective one of the first and the second optical inputs of the optical circuit are aligned.

Abstract: A tunable dispersion compensator that includes a free propagation region and an adjustment region. The free propagation region includes a first end and a second end, and allows an input lightwave signal having component signals with different wavelengths to propagate from the first end to the second end. The adjustment region directs the input lightwave into portions of the input lightwave, adjusts a characteristic of the portions of the input lightwave signal at the second end, and directs the adjusted portions of the input lightwave signal back towards the first end. The adjusted portions of the input lightwave signal combine at the first end to generate an output lightwave signal having a phase profile that is different from a phase profile of the input lightwave signal.

Abstract: In an optical device, each of a plurality of radiation sources generates a separate different wavelength output signal to a wavelength locking device wherein a grating device receives the separate wavelength output signals from the plurality of radiation sources. The grating device generates a multiplexed wavelength output signal at a zero diffraction order output port thereof, and resolves separate symmetric wavelength?? and wavelength?? output signals at separate predetermined locations within at least one non-zero diffraction order thereof for each of the radiation sources. Each of a plurality of radiation detectors is coupled to receive a separate one of the symmetric wavelength?? and wavelength?? output signals and generate an output signal representing the magnitude of the received wavelength output signal.

Abstract: An optical system has a transmission filter device, a feedback mechanism, and one or more radiation sources. Each radiation source generates an output signal with a predetermined wavelength band and polarization and is coupled to a separate input port of the transmission filter device. The transmission filter device, which is responsive to output signal from each radiation source, generates an output signal from at least one output port thereof. The feedback mechanism is coupled to at least one output port of the transmission filter device for providing a feedback signal that is directed back through the transmission filter device to each of the radiation sources for stabilizing each of the radiation sources. The apparatus is polarization maintaining wherein the one or more radiation sources, the transmission filter device, and the feedback mechanism are interconnected such that principle axes of polarization thereof are substantially aligned.

Abstract: In a star coupler, a Free Propagation Region (FPR) is bounded by a first interface and a second opposing interface, and guides an input signal launched from the first interface in a predetermined first plane while allowing the input signal to travel unguided in a predetermined second plane in the FPR which is orthogonal to the first plane. A plurality of output waveguides are formed in an array and terminate at the second interface of the FPR. The axis of each output waveguide at the second interface is separated from an axis of an adjacent output waveguide by a predetermined distance “t”. An input waveguide is split into a plurality of subsections which each terminate at the first interface of the FPR. The subsections of the input waveguide are arranged for simultaneously launching parts of the input signal into the FPR which diffracts and produces mode patterns at the second interface having a maximum intensity at inputs of each of the output waveguides, and a low intensity elsewhere.

Abstract: A plurality of n light sources are coupled to an optoelectronic module by first coupling a light detector to an optical output port of the optoelectronic module after the module is attached to a carrier member. The plurality of n light sources are sequentially moved adjacent a separate one of a plurality of n optical input ports of the optoelectronic module while pulsing the light source being moved with a low power signal sufficient to prevent failure of the light source. Each light source is permanently affixed adjacent the associated separate one of the n optical input ports when a maximum light intensity signal propagating through the optoelectronic module from that light source is detected by the light detector. A heat dissipating means is attached to a base of the carrier member capable of removing sufficient heat from the n radiation sources and the module to prevent overheating during normal operation thereof.