Device for generating an FSK-modulated optical signal with two different polarisation states for an optical transmission system with an optical heterodyne FSK receiver having two filters

摘要

In an optical transmission system with two filter FSK heterodyne receiver polarization-independent reception is possible, has when the power supplied to the optical signal receiver stands two mutually orthogonal Polarisationszu in a certain way. A known device for generating such a signal comprises means for converting a polarized FSK-modulated optical transmission signal in the desired optical signal. In this device, the frequency deviation .DELTA.f must be very large chosen over the data rate. In the invention, however, the frequency deviation can be freely selected.; For this purpose, the means for converting the polarizing th optical transmission signal (S₁ (t)) in the each other or thogonalen polarization states having optical signal (S₂ (t)) of a d from a digital data signal (t) ge controlled polarization switch.; heterodyne reception application for optical transmission systems with excess