Abstract: Disclosed are an optical amplifier and an optical transmission system using the same in which not only can the dispersion of optical waveguide paths for optical amplification be easily and sufficiently compensated, but also the waveform degradation of signal light can be restrained. An optical amplifier according to one embodiment of the present invention comprises at least two erbium-doped fibers 10 and 20, having erbium doped to optically amplify signal light with the pump light, and having dispersion different from each other in sign, and being connected together in series, and two pump light sources 11 and 12 for supplying pump light to them.

Abstract: In a method of amplifying optical input signals over a wide bandwidth, the optical input signals are applied to an optical waveguide made from a rare-earth-doped amorphous material (e.g., erbium-doped yttrium aluminum oxide material). The optical input signals include optical signals having wavelengths over a range of at least 80 nanometers, and, preferably, over a range of at least 160 nanometers. Pump light is applied to the optical waveguide to cause the waveguide to provide optical gain to the optical input signals. The optical gain causes the optical signals to be amplified within the waveguide to provide amplified optical signals over the extended 80-160-nanometer range, including, in particular, optical signals having wavelengths at one end of the range and optical signals having wavelengths at a second end or the range.

Abstract: Optical network equipment is provided. The optical network equipment may include optical amplifiers. Control units may be used to control components in the equipment such as gain stage pump lasers. Sensor data may be obtained from sensors in the equipment. The control units may store the sensor data and control data and other information on the operation of the equipment. The stored data may be used in troubleshooting, network maintenance, and set up procedures. Data may be saved when a data storage command is received by the equipment or may be saved when data storage trigger criteria are satisfied. A user may be provided with the ability to customize the trigger criteria and the data storage parameters.

Abstract: An amplification architecture for WDM receiver systems. The WDM channel grid is divided into groups of adjacent channels. A separate optical amplifier is provided for each channel with a single pump being shared among the channels of each group. The gain experienced by channels of a given group may be adjusted by varying the power of the group's pump. This approach allows equalization of received channel power such that all channels fall within the desired dynamic range. The amplification architecture may be implemented in a space-efficient manner at low cost.

Abstract: An external-resonator laser system having multiple laser elements is configured to permit each laser to undergo individual amplification notwithstanding optical beam combination. In this way, overall output power may be scaled in a desired fashion, depending on the selected characteristics of the optical amplifier elements. To achieve additional power, each of the amplifiers may implemented as a phased array. Viewed more generally, a phased-array configuration affords beam combining in two stages, with each contributing input source itself composed of multiple sources whose outputs have been combined. If each phased-array source emits at a different wavelength, this design offers a multi-wavelength output whose power level may be scaled in accordance with the number and character of the devices forming each phased array.

Abstract: Optical amplifiers and optical network equipment are provided that have optical gain stages for amplifying optical signals on a fiber-optic communications link. The optical gain stages may be based on optically pumped fiber such as rare-earth-doped fiber. The fiber may be optically pumped using laser diode pumps. A control unit may be provided in the amplifiers or other equipment to control the laser diode pumps. Optical monitors may be used to measure the optical signals in the amplifiers or other equipment. The pump powers of the laser diode pumps may be adjusted in real time by the control unit based on the measured optical signals to suppress gain transients due to input power fluctuations on the link. To minimize the impact of pump-induced noise, the control unit may avoid operating the laser diodes at powers at which the laser diodes are most susceptible to mode partition noise.

Abstract: An optical amplifier is implemented which can reduce its size and cost by using a smaller number of components. Signal light coupled by an optical combiner with pump light fed from a pumping light source is incident on an EDF (erbium-doped fiber) to be pumped and amplified by the pump light, is emitted from the EDF to be incident on a second optical circulator and output from its second port, passes through an optical component to be fed back to the second optical circulator and launched into the EDF from the second optical circulator, passes through the EDF again in the direction opposite to the first passing direction followed by passing through the optical combiner, and is output from the third port of a first optical circulator.

Abstract: An optical transmission system comprising a first optical waveguide suitable for transmitting a first information signal, a second optical waveguide suitable for transmitting a second information signal, and input means for providing an electro magnetic radiation signal into said first waveguide, said signal being suitable for providing Raman amplification of the information signals, the system further comprising an optical coupling between said waveguides, arranged to transmit at least a portion of the Raman amplification signal from the first waveguide to the second whilst substantially blocking the transmission of the information signals between the waveguides.

Abstract: A switchable dynamic gain-flattened optical amplifier with wide adjustable gain range is provided. Optical signals are amplified through common amplification such that the gain is approximately common to all optical signals. Further, gain specific amplification is then achieved through distinct amplification wherein the optical signal is routed through one of N parallel amplification paths each having its well-designed gain. The amplifier makes use of a control circuit to self-adjust quickly and respond to changes in input conditions, operating conditions of the optical amplifier and gain requirements while maintaining gain flatness and a low noise figure (NF) over a broad optical bandwidth and a wide range of gain levels. The optical amplifier is highly desirable in dense wavelength-division-multiplexed (DWDM) systems for responding to changes in operating conditions due to link loss, pump deterioration, channel add/drop, and network reconfigurations.

Abstract: An optical amplifier is provided from a body 21, at least part 25 of which is doped with a rare earth such as erbium. At least one waveguide 47 extends through the doped part of the body. Pump light 51 is input on a side face 35 of the body and is distributed in the body over the length of the waveguide 47. A reflective coating 57 may be provided away from the pump light input, including on the opposite face 37 to the pump light input, to multiply reflect pump light within the body 21 to distribute the pump light within the body. The body may be in the form of a slab.

Abstract: In a diode-pumped laser amplifier the inventive object is to increase the tolerance of the amplifier arrangement relative to variations of the input parameters significantly, so that fine-tuning is no longer necessary for guaranteeing the stability of the amplifier. Into a laser-active solid-state medium where a thermal lens of a strength which is different in orthogonal planes is generated in consequence of the irradiated pump radiation, a laser beam to be amplified is directed into the laser-active solid-state medium while being focused in the plane with a strong thermal lens, wherein a beam waist that is being generated lies in the area of the thermal lens. The laser amplifier can be used for amplifying the radiation of an oscillator.

Abstract: Light signals of first to n-th bands amplified en bloc undergo proper attenuation through an adjustable optical attenuator in conformance with attenuation in an optical fiber connected to input of an optical amplifying repeater apparatus, whereon the light signals are demultiplexed or separated into individual bands and amplified by first to n-th fixed-gain optical amplifiers (#1, . . . , #n) each having a high fixed gain in the respective bands to be subsequently multiplexed by an optical multiplexer and then sent out onto a transmission line. A monitoring light branching device extracts a part of light power of a specific monitoring wavelength, which is then fed to an adjustable attenuator control circuit which controls the attenuation factor of the adjustable optical attenuator so that the light power of the specific wavelength remains constant. The gain of the optical amplifying repeater apparatus at the specific wavelength can thus be determined.

Abstract: Data transmitted on optical fiber over long distances is subject to the introduction of errors at the receiving end, caused by distortions and alterations of the original data. Raising the transmission power to increase the level of signals at the receiving end also increases errors due to non-linear characteristics of the fiber. The invention optimizes launch power by assessing error rates due to amplified spontaneous emissions and due to four wave mixing, so that signal to noise ratios due to these causes exceed threshold levels while enabling launch power to be maximized.

Abstract: An optical amplification system has an active fibre section having an optical fibre 10 and containment means 8, 12 containing light of a specific wavelength within the active fibre section. The specific wavelength of light is the result of the spontaneous transition of photons. The contained photons stimulate further photons emissions, which depopulates energy levels involved in the amplification process.

Abstract: An optical device comprises an optical amplifier to amplify optical signals, optical pumps coupled to and providing optical pump power to least one amplifying stage of the optical amplifier, so as to produce gain in the said optical amplifier and, a tunable optical filter coupled to the optical amplifier. The optical filter changes the gain slope of the optical amplifier in response to a change in a single parameter of the optical filter. The optical amplifier also includes at least one controller adjusting said single parameter of the optical filter and controlling the optical pumps.

Abstract: A system and method for amplifying an optical signal within an optical waveguide amplifier including providing at least one optical waveguide amplifier having an input for receiving an optical source signal therein and an output, wherein a forward pumping direction extends from the input to the output and rearward pumping direction extends from the output to the input. The system also includes providing at least one excitation light source in optical communication with the optical waveguide amplifier and capable of generating at least one excitation light. The system further includes amplifying the source signal by pumping a first excitation light from the excitation light source in the rearward pumping direction, and amplifying the source signal by simultaneously pumping a second excitation light from the excitation light source in the forward direction.

Abstract: The optical fiber pumping system includes a connector that is adapted to selectively communicate with an external pump system. The connector communicates with an onboard pump multiplexer which also receives input from an on-board pump via a connector. The on-board pump may be hot swapped by connecting an external pump system to the connector and coordinating the power up of the external pump system with the power down of the on-board pump to replace a failed on-board pump with a new pump.

Abstract: An optically active phosporus-silicate glass when pumped to directly excite Er ions, provides gain in 1565 nm to 1620 nm range and comprises in weight percent: SiO2 50 to 92%; Er2O3 0.01 to 2%; P2O5 greater than 5%; and Al2O3 0.0 to 0.3%.

Abstract: An active optical amplifier in which a unitary optical amplifier constructed from a unitary optically transparent chip that has been doped so as to be optically active, amplifies incoming signal photons when excited by a pump laser of sufficient energy. The unitary optical amplifier receives input photons and pump laser energy and provides output photons that have the same spatial orientation and phase as the corresponding input photons. A laser direction and ranging (LADAR) may be constructed from the active optical amplifier by further including first imaging optics to focus the input photons onto the surface of the unitary optical amplifier and second imaging optics to focus the output photons from the active unitary optical amplifier onto a focal plane image sensor array. The electronic signals from the focal plane image sensor array may then be displayed on a conventional display.

Abstract: An optical node and method for operation in an ultra long haul backbone network that provides DWDM optical transmission and wavelength networking functionalities are disclosed. The optical node is designed with capabilities for amplification, dispersion compensation, and add/drop functionalities. In one embodiment, three erbium-doped fiber amplifier (EDFA) are cascaded using low nonlinearity and low loss dispersion compensating module (DCM).