Patent ID: 7376300

Claim:
A variable optical dispersion compensating module comprising: (a) an optical dispersion compensating unit comprising: an input switch, a bypass path, a loop optical dispersion compensating fiber having a predetermined optical dispersion amount, an output switch, and said bypass and said loop fiber being connected to said input switch and to said output switch; (b) a plurality of said units connected in series; (c) an input connector located at the input to the variable optical dispersion compensating units; (d) an output connector located at the output of the variable optical dispersion compensating units; (e) a single optical attenuator provided between said input connector and said output connector; and (f) a control device that is connected to the optical attenuator and connected to said input and output switches of said plurality of said units to read switching states of said switches and control said optical attenuator based on the read switching states.