Silicon Microring Modulator for Dispersion Uncompensated Transmission Applications

We report an investigation of the negative-chirp characteristics of an overcoupled silicon microring modulator with carrier-depletion p-n junction for 10-Gb/s transmission over single-mode fiber up to distances of 100 km. The modulator exhibits over 15 dB extinction ratio for an approximately 5 V peak-to-peak driving voltage. The on/off chirp α-parameter is estimated to be less than -1 for an optimally designed device. This negative chirp leads to a robust dispersion tolerance which is verified by bit error rate measurements. The results show that the device can support transmission with a negative power penalty up to 50 km, while the power penalty at 100 km is as low as 2.5 dB.