Method and apparatus for monitoring noise figure of optical amplifier

摘要: A method and an apparatus for monitoring the noise figure of optical amplifier such as used in linear repeaters transmission system formed by cascaded repeaters. The includes at least one amplifying input signal light a narrow bandwidth filter removing amplified spontaneous emission (ASE) generated amplifier. gain detector is provided to detect ASE power detects splitter splitting entering into local oscillator generating having wavelength displaced from light. split coupled with oscillator. An makes heterodyne detection electrical band-pass extracts obtained detector. calculator calculates according detected