Slow-Light-Enhanced Silicon Optical Modulators Under Low-Drive-Voltage Operation

[EN] The integration of nanophotonics components with advanced complementary metal-oxide-semiconductor (CMOS) electronics requires drive voltages as low as 1 V for enabling next-generation CMOS electrophotonics transceivers. Slow-light propagation has been recently demonstrated as an effective mechanism to enhance the modulation efficiency in free-carrier-based electrooptical silicon modulators. Here, we exploit the use of slow light to reduce the driving voltage of carrier-depletion-based Mach-Zehnder modulators. The slow-light phase shifter consists of a p-n junction positioned in the middle of a corrugated waveguide. A modulation efficiency as high as V pi L pi similar to 0: 6 V . cm is achieved, thus allowing data transmission rates up to 10 Gb/s with a 1.5-V-pp drive voltage and an insertion loss of similar to 12 dB. The influence of the drive voltage on the modulation speed as well as the variation of the insertion losses with a group index is also analyzed and discussed.© 2009-2012 IEEE.