New all-optical RIN suppressing, image rejection receiver with efficient use of LO- and signal-power

An all-optical method of achieving a heterodyne signal is presented whereby the local oscillator (LO) relative intensity noise (RIN) and the image channel have been suppressed while efficient use of both LO and signal power is made. This is achieved with only one photodetector, compared to four for the conventional optical-electrical configuration. A 15-dB reduction of LO RIN can be obtained for a relative channel bandwidth of 50%. The image channel of the same bandwidth is suppressed by almost 20 dB.>