Abstract: A system and method for providing eye-safety protection during operation of distributed Raman amplifiers based on the application of continuous out-of-band amplified spontaneous scattering (ASS) monitoring in an optical communication network span coupled to the Raman amplifier, and real-time detection and analysis of changes in the monitored ASS power level, The system includes at least one Raman pump for introducing Raman energy into the span, a monitoring unit for performing the continuous ASS monitoring, and a control unit operative to detect and analyze in real-time changes in the ASS power, and upon determination that such changes indicate an open span, to reduce the level of the Raman pump energy entering the span to a safe level.

Abstract: A system and method for providing eye-safety protection during operation of distributed Raman amplifiers based on the application of continuous out-of-band amplified spontaneous scattering (ASS) monitoring in an optical communication network span coupled to the Raman amplifier, and real-time detection and analysis of changes in the monitored ASS power level, The system includes at least one Raman pump for introducing Raman energy into the span, a monitoring unit for performing the continuous ASS monitoring, and a control unit operative to detect and analyze in real-time changes in the ASS power, and upon determination that such changes indicate an open span, to reduce the level of the Raman pump energy entering the span to a safe level.

Abstract: A system and method for providing eye-safety protection during operation of distributed Raman amplifiers based on the application of continuous out-of-band amplified spontaneous scattering (ASS) monitoring in an optical communication network span coupled to the Raman amplifier, and real-time detection and analysis of changes in the monitored ASS power level, The system includes at least one Raman pump for introducing Raman energy into the span, a monitoring unit for performing the continuous ASS monitoring, and a control unit operative to detect and analyze in real-time changes in the ASS power, and upon determination that such changes indicate an open span, to reduce the level of the Raman pump energy entering the span to a safe level.

Abstract: A high efficiency, high performance optical amplifier includes an amplification stage comprised of two Erbium doped fiber (EDF) gain sections separated by a variable optical attenuator (VOA). A single pump serves to pump both EDF sections. A high dynamic gain range is achieved by an interplay between the action of the VOA, and the pump energy absorption mechanisms in each gain section, which are dominated by the saturation characteristics of each of the EDFs. In a preferred embodiment of the method, input signals are coupled with a pump signal into a first EDF gain section in which the energy absorption mechanisms provide first amplified signals that are correlated with a residual pump signal. At the first EDF gain section output, the combined amplified signals and residual pump signal are decoupled, the amplified signals being attenuated in the VOA while the residual pump signal being routed around the VOA.

Abstract: A method and apparatus for optical amplification with a large dynamic gain range in both the non-linear (1530-1540 nm) and linear (1540-1565 nm) regimes of the C-Band. The large dynamic gain range is achieved by the synergistic operation of a dual-stage Erbium-doped Fiber Amplifier (EDFA) having a self-saturating Thulium-doped fiber inserted between the two stages. The Thulium-doped fiber saturation is determined by the output power of the first EDFA stage, and the synergistic, combined operation of both EDFA stages and the self-saturating absorber is controlled by appropriate algorithms and software.

Abstract: An apparatus and method for a self-adjusting Raman amplifier for fiber optic transmission lines incorporating a line diagnostic mechanism in order to calculate, control and optimize the operating parameters for the amplifier. A Line Analyzing Unit, adjacent to the Raman pump unit, operates before the Raman pump is enabled and during operation, and characterizes the transmission line. The Line Analyzing Unit determines and characterizes the types of optical fibers installed along the transmission line and calculates and optimizes the pump or pumps power in order to achieve optimum gain, gain equalization and gain tilt. The Line Analyzing Unit may also determine if there is an optical loss or reflection in the optical fiber that can be destructive when the high power Raman pump is operating.

Abstract: This invention describes an apparatus and method for a self adjusting Raman amplifier for fiber optic transmission lines incorporating a line diagnostic mechanism in order to calculate, control and optimize the operating parameters for the amplifier. This need arises because the amplifier gain medium is the transmission line itself and the amplifier properties depend on the optical fiber properties along the first tens of kilometers of the transmission line from the pump. A Line Analyzing Unit, adjacent to the Raman pump unit, operates before the Raman pump is enabled and during operation, and characterizes the transmission line. The Line Analyzing Unit determines and characterizes the types of optical fibers installed along the transmission line and calculates and optimizes the pump or pumps power in order to achieve optimum gain and gain equalization.