Method and system for optical heterodyne detection of an optical signal

摘要

An optical heterodyne detection system in accordance with an embodiment of the invention includes two optical receivers (232 and 242) for separately measuring the power of an input signal (202) and a local oscillator signal (206) before the signals are combined. The measurements of the input signal and the local oscillator signal are then utilized by a processor (216) to enhance the heterodyne signal to noise ratio by removing the intensity noise contributed by the input signal and the local oscillator signal. By measuring portions of the input signal power and the local oscillator signal power and then subtracting out the scaled quantities from the photocurrent measurement during signal processing, the signal to noise of the heterodyne signal is improved beyond that which is accomplished by known balanced receivers. <IMAGE>