Abstract: A fiber-based master optical power amplifier (MOPA) is configured to utilize a pump source that operates in pulse mode with the arrival time of the pump pulses coordinated with the arrival time of the input pulses. The width of the pump pulses is also controlled, thus providing a mechanism for controlling both the amount of pump energy injected into the fiber amplifier, as well as the overlap in time between the pump pulse and the seed pulse. As the pulse repetition interval (PRI) of the input seed pulse changes, the timing of the pump pulses and their width are also changed so that a “constant gain” environment is created within the amplifying medium, providing an essentially constant energy output pulse, regardless of differences in ASE generated during different PRIs.

Abstract: A fiber-based master optical power amplifier (MOPA) is configured to utilize a pump source that operates in pulse mode with the arrival time of the pump pulses coordinated with the arrival time of the input pulses. The width of the pump pulses is also controlled, thus providing a mechanism for controlling both the amount of pump energy injected into the fiber amplifier, as well as the overlap in time between the pump pulse and the seed pulse. As the pulse repetition interval (PRI) of the input seed pulse changes, the timing of the pump pulses and their width are also changed so that a “constant gain” environment is created within the amplifying medium, providing an essentially constant energy output pulse, regardless of differences in ASE generated during different PRIs.

Abstract: A fiber-based master optical power amplifier (MOPA) is configured to utilize a pump source that operates in pulse mode with the arrival time of the pump pulses coordinated with the arrival time of the input pulses. The width of the pump pulses is also controlled, thus providing a mechanism for controlling both the amount of pump energy injected into the fiber amplifier, as well as the overlap in time between the pump pulse and the seed pulse. As the pulse repetition interval (PRI) of the input seed pulse changes, the timing of the pump pulses and their width are also changed so that a “constant gain” environment is created within the amplifying medium, providing an essentially constant energy output pulse, regardless of differences in ASE generated during different PRIs.

Abstract: A fiber-based master optical power amplifier (MOPA) is configured to utilize a pump source that operates in pulse mode with the arrival time of the pump pulses coordinated with the arrival time of the input pulses. The width of the pump pulses is also controlled, thus providing a mechanism for controlling both the amount of pump energy injected into the fiber amplifier, as well as the overlap in time between the pump pulse and the seed pulse. As the pulse repetition interval (PRI) of the input seed pulse changes, the timing of the pump pulses and their width are also changed so that a “constant gain” environment is created within the amplifying medium, providing an essentially constant energy output pulse, regardless of differences in ASE generated during different PRIs.

Abstract: A method for tuning and improving the performance of an optical communication system comprising al link that includes optical amplifiers and, optionally, active and/or passive optical components such as, e.g., DWDM's, WADM's, and optical cross-connects, includes preferentially shaping and, in particular, flattening, with respect to the input power spectrum, the output power spectrum from the amplifier, component or of the link. A flattened output power spectrum is obtained by modifying the gain spectrum operating on the respective input power spectrum. Feedback for such gain modification is typically provided by optimizing the optical signal to noise ratio of each channel of the respective output power spectrum. A system link, an optical amplifier, and optical components having flattened output power spectra are also described.

Abstract: A wavelength selective optical cross-connect includes a first demultiplexor feeding into individually removable modules that in turn feed a first multiplexor, such that the cross-connect is expandable and repairable on a wavelength or waveband basis. The modules desirably include multiple optical components in the optical path, with components in each module matched to others in that module to provide module-to-module variation below that of the variation in module components. The modules desirably include an additional demultiplexor and multiplexor. The modules also desirably include wavelength or narrowband amplification together with power equalization. The modules may also include a switch fabric.

Abstract: An optical amplifier includes an optical feedback resonant laser cavity (OFRC) including a power dependent loss element (PDLE) having the characteristic that as the incident laser power on the PDLE increases the cavity loss decreases. The OFRC with the PDLE provides optical gain control or optical power control for a WDM amplifier or a single channel power equalization amplifier (PEA), respectively. A 1×N×N WADM node incorporating more than one of these amplifiers, at least some of which commonly share a pump source, and a method for controlling a transient power change in a single channel optical amplifier or reducing a DC gain error in a WDM optical amplifier that are subject to dynamically variable operating conditions at an input of the amplifier, are also disclosed.

Abstract: Techniques for controlling the shape of the gain spectrum of an optical amplifier (13) based on the temperature and level of inversion of the amplifier's amplifying medium (20) are provided. An increase in temperature for an amplifying medium having a high level of inversion results in an increase in gain for longer wavelengths relative to shorter wavelengths, i.e., a counterclockwise tilt of the gain spectrum, while an increase in temperature for an amplifying medium having a lower level of inversion results in the opposite effect, i.e., a clockwise tilt. These effects can be used to compensate for changes in the operating conditions of the amplifier, e.g., to compensate for changes in signal powers. The effects of thermal tuning are especially useful in WDM systems employing multi-stage amplifiers.

Abstract: A gain-controllable optical fiber amplifier having an input for receiving an optical signal and an output for providing an amplified optical signal. A first gain stage is coupled between the input and output and includes a first optical fiber and a first pump. A second gain stage is coupled in series with the first stage and includes a second optical fiber and a second pump. The amplifier includes a pump controller for controlling the first and second pumps and adjusting the power output of the first and second pumps to maintain a substantially constant gain. The controller decreases the power output from each of the first and second pumps as a function of minimum output of each pump to minimize noise. Accordingly, the present invention advantageously controls the gain applied to an optical fiber in a manner that minimizes the amount of noise that may otherwise be introduced into the optical signal, especially when the input power is comparable to the backward amplified spontaneous emission of the amplifier.