CONTROLLABLE OPTICAL ADD/DROP MULTIPLEXER

摘要

The invention relates to a method for operating a controllable selective optical input/output channel for a fibre-optic communication system provided with 2^N of wavelength-division multiplexing channels, whose optical frequencies are retunable, at a constant wavelength shifting ?? between adjacent channels with the aid of the inventive controllable optical input/output multiplexers (70, 80, 90) which comprise multi-stage structures of optical filters ({75-i}, {85-i} {95-i}), which are connected in different manner and provided with devices, for example electrooptical and thermooptical phase shift devices, for controllingly tuning the transmission coefficients thereof. The optical filters are embodied in the form of single stage (20), two-stage (40) and/or multi-stage (60) asymmetric Mach-Zehnder interferometers. The demultiplexer can be produced according to integrated optic technique in the form of a monolithic solid-state device.