A tunable dispersion compensating MEMS all-pass filter

• Published in: IEEE photonics technology letters Vol. 12; no. 6; pp. 651 - 653
• Main Authors: Madsen, C.K., Walker, J.A., Ford, J.E., Goossen, K.W., Nielsen, T.N., Lenz, G.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-06-2000; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Biomembranes; Channels; Delay; Devices; Dispersions; Group delay; Holes; Micromechanical devices; Noise levels; Optical fiber devices; Optical fiber polarization; Optical filters; Packaging; Passband; Reflectivity; Ripples; Silicon; Tuning
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/68.849073

A tunable dispersion compensating filter based on a multistage optical all-pass filter with a microelectromechanical (MEM) actuated variable reflector and a thermally tuned cavity is described. A two-stage device was demonstrated with a tuning range of /spl plusmn/100 ps/nm, 50-GHz passband and a group delay ripple less than /spl plusmn/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 <2 dB/stage avoids the need for a circulator. By cascading four stages, a passband to channel spacing ratio of 0.8 is obtained that allows both 40 Gb/s nonreturn-to-zero (NRZ) and return-to-zero (RZ) signals to be compensated.