Highly Efficient and Compact Silicon based Novel Michelson Interferometer Modulator

We present a novel common mirror high-speed silicon Michelson interferometer (CMMI) modulator with two 380 μm-long PN diode phase shifters. The general Michelson Interferometer (MI) optical structure is an enhanced Mach- Zehnder interferometer (MZI) with both arms incorporated with reflective mirrors. In the proposed design, these two reflective mirrors are replaced by a single mirror employed as closed waveguide feedback loop at the output of 2×2 splitter/combiner unit. The light in the CMMI travels back and forth along the phase shifting waveguides and therefore doubles the effective length of light-carrier interaction. The proposed CMMI modulator shows high efficiency having a low figure of merit VπLπ of 1.71 V.cm to 0.85 V·cm for P = N = 1e
¹⁷
cm
^-3
under the bias of 0.5 V to -4 V for a reduced insertion loss of 3.5 dB footprint, device count and fabrication variability. At 10 Gbit/s bitrate, extinction ratio of 12.5 dB and BER<; 10e
^-12
is achieved thereby providing a great potential in the future optical interconnects.