Optical amplifier

摘要

A high fidelity optical amplifier having a stable amplification gain is presented. The problem of signal distortion in an output optical signal caused by an imbalance of light energy generation and consumption within the optical fiber is resolved by generating a delayed correction signal to be used in a feedback control circuitry. An incoming optical signal is split into two signals: one split signal is forwarded to a photo-detector element for generation of the correction signal while the other split signal is forwarded to a signal delay circuit. The optical delay circuit delays the timing of inputting the correction signal into output optical fiber for a specific duration of time to attain a full amplification gain within the optical fiber. The correction signal generation circuit performs differentiation of an electrical input signal followed by detection and selection of a maximum amplitude over a standard reference voltage. The selected signal acts as trigger to the pulse generation circuit and waveform correction circuit in conjunction with a variable-gain amplifier to provide a correction signal to maintain the amplification gain of the optical fiber at a constant level. The resulting output signal is distortion-free and stable over a prolonged period of time.