METHOD FOR MAKING AN HETERODYNE OPTICAL RECEIVER INSENSITIVE TO PHASE AND/OR POLYRISATION FOR A DPSK OR ASK MODULATED EMITTING SIGNAL

摘要

2.1 For DPSK-modulated or ASK-modulated transmission signals, a simple method to achieve phase-insensitive and/or polarisation- insensitive optical heterodyne reception for such a signal is specified, using an intermediate frequency which is very low in comparison with a data rate of these signals. …2.2 For this purpose, for each clock cycle of the transmission signal (S), the phase of this signal (S) is sampled at the start (A1) and in the centre (M) of the clock period (T) of this clock cycle between 0 DEG or 90 DEG and/or the polarisation of this signal (S) is sampled at least at the start (A2) of the second and at the start (A4) of the fourth quadrant of this clock period (T). The transmission signal (S), sampled in this manner, is received by a simple optical heterodyne receiver (ÜE) which has the special feature that an intermediate frequency filter (ZFF) is an integrator which integrates in each case over a quadrant of the clock period (T). The method can also be carried out in two different variations of the method. …2.3 Optical heterodyne reception ……