Tunable dispersion compensator and method for tunable dispersion compensation

摘要

A tunable dispersion compensator and a tunable dispersion compensation method having an excellent dispersion compensation characteristic are provided. A tunable dispersion compensator 201 is constructed of first to fourth ring resonators 202₁ to 202₄ connected in series along a common linear waveguide 203. The linear waveguide 203 is provided with first to fifth mode filters 204₁ to 204₅ in such a way as to sandwich the ring resonators 202₁ to 202₄ respectively. These mode filters 204₁ to 204₅ eliminate high-order mode noise components which transmit through the linear waveguide 203. The mode filters 204₁ to 204₅ are constructed with the width of a central waveguide reduced or in a curved shape.