25 Gbit/s silicon microring modulator based on misalignment-tolerant interleaved PN junctions

A high-speed depletion-mode silicon-based microring modulator with interleaved PN junctions optimized for high modulation efficiency and large alignment tolerance is demonstrated. It is fabricated using standard 0.18 mu m complementary metal-oxide-semiconductor processes and provides low V(pi)L(pi)s of 0.68 V.cm to 1.64 V.cm with a moderate doping concentration of 2 x 10(17) cm(-3). The measured modulation efficiency decreases by only 12.4% under +/- 150 nm alignment errors. 25 Gbit/s non-return-zero modulation with a 4.5 dB extinction ratio is experimentally realized at a peak-to-peak driving voltage of 2 V, demonstrating the excellent performance of the novel doping profile. (C) 2012 Optical Society of America