A tunable dispersion compensating MEMS all-pass filter

A tunable dispersion compensating filter based on a multistage optical all-pass filter with a microelectromechanical (MEM) actuated variable reflector and a thermally toned cavity is described. A two-stage device was demonstrated with a tuning range of +/-100 ps/nm, 50-GHz passband and a group delay ripple less than +/-3 ps. The device has negligible polarization dependence and is suitable for single or multiple channel compensation. An off-axis, two-fiber package with an excess loss