Tunable Dispersion Compensation at 40Gb/s using a Multicavity Etalon All-Pass Filter, with NRZ, RZ and CSRZ Modulation

We present a multichannel tunable dispersion compensator based on multicavity all-pass etalons that is capable of operation at 40Gb/s. The device has a tuning range of +200/-220 ps/nm with a group delay ripple +/- 5 ps over a channel bandwidth of 80GHz, an overall loss of 5.2 dB, very low insertion loss ripple, and can operate on any channel on a 200GHz grid over the C-band. In addition, we present system performance results at 40 Gb/s using NRZ, RZ and CSRZ modulation, compensating up to 45 km of non-zero dispersion shifted fiber (NZDSF). Our results show that this device introduces very little excess system penalty with signal frequency drifts of up to 20GHz when operated near the center of its tuning range. For single channel experiments with fiber, the system penalty increase versus signal detuning is more significant, but can be reduced by dynamically optimizing the device dispersion during detuning. Finally, we demonstrate simultaneous compensation of 4 channels across the C-band over 25 km of NZDSF.