Variable dispersion compensation equipment, optical transmission system using it and method of setting dispersion compensation quantity

A variable dispersion compensation equipment comprising an optical switch provided with first, second and third input terminals and first, second and third output terminals, a first dispersion compensating module disposed between the first output terminal and the first input terminal, a second dispersion compensating module disposed between the second output terminal and the second input terminal, and a controller for controlling change-over of the optical switch, wherein:

• optical signals inputted to the third input terminal, after traveling through the first dispersion compensating module or the second dispersion compensating module, or the first dispersion compensating module and the second dispersion compensating module, are outputted from the third output terminal.

An optical transmission system comprising an optical transmitter for sending out optical signals, an optical receiver for receiving the optical signals, and a variable dispersion compensation equipment for compensating dispersion of the optical signals attributable to a transmission path, wherein:

• said variable dispersion compensation equipment includes an optical switch having M input terminals and M output terminals and capable of connecting any desired one of the input terminal and one of the output terminals, N input units connected to the input terminals, N output units connected to the output terminals, two or more but (M−N) or fewer dispersion compensating modules provided between one of the output terminals and one of the input terminals, and a controller for controlling change-over of the optical switch, wherein optical signals inputted to one of the input units are outputted, after being caused to pass at least one of the dispersion compensating modules, from one of the output units.

An optical transmission system comprising an optical transmitter for sending out optical signals, an optical receiver for receiving the optical signals, and a variable dispersion compensation equipment for compensating dispersion of the optical signals attributable to a transmission path, wherein:

• said variable dispersion compensation equipment comprises an optical switch provided with first, second and third input terminals and first, second and third output terminals, a first dispersion compensating module disposed between the first output terminal and the first input terminal, a second dispersion compensating module disposed between the second output terminal and the second input terminal, and a controller for controlling change-over of the optical switch, wherein optical signals inputted to the third input terminal, after traveling through the first dispersion compensating module or the second dispersion compensating module, or the first dispersion compensating module and the second dispersion compensating module, are outputted from the third output terminal.

A method of a setting dispersion compensation quantity wherein terminals of an optical switch which have unused dispersion compensating modules connected thereto are searched for,

• a dispersion compensation quantity that can be set on any of the unused dispersion compensating modules is displayed, and
• said optical switch is set so as to achieve a selected dispersion compensation quantity.