Abstract: An optical amplifier having a substantially flat response over a multi-channel bandwidth for signals which have different input levels. It utilizes input and output photodetectors for detecting amplitude variations. The gain can be determined by a microprocessor receiving signals derived from the photodetectors, which causes change in the gain of the amplifier. The microprocessor calculates output ASE noise content at different amplifier input levels and subtracts that noise from the total power received by the output detector thereby determining an accurate amplifier gain value. The gain setting offered by the amplifier will then be the same as what is desired by a network management system.

Abstract: A broadband light amplifier comprising a pair of signal transmission and amplification arms, one for carrying a short wavelength signal in a short optical wavelength band and another for carrying a longer wavelength signal in a longer optical wavelength band, an optical amplifier in each arm for amplifying a respective signal carried therein, and a wavelength division optical multiplexer for combining the amplified signals into a single optical fiber, the amplifier being devoid of a circulator.

Abstract: An optical light source signal generator comprising an optical amplification medium for generating amplified spontaneous emission (ASE), having forward and backward light propagating ports for outputting output and backward optical light respectively, a reflector for reflecting the backward propagating optical light back toward the backward light propagating port, and an optical light spectrum reshaper interposed between the reflector and the backward light propagating port for transmitting the reflected light to the backward light propagating port with a wavelength dependence having a reduced amplitude in a band coinciding with an undesired high gain band of the optical amplification medium.