High-speed silicon Michelson interferometer modulator and streamlined IMDD PAM-4 transmission of Mach-Zehnder modulators for the 2 μm wavelength band

We demonstrate high-speed silicon modulators optimized for operating at the wavelength of 2 mu m. The Mach-Zehnder interferometer (MZI) carrier-depletion modulator with 2 mm phase shifter has a single-arm modulation efficiency (V-pi.L-pi) of 2.89 V.cm at 4 V reverse bias. Using a push-pull configuration it operates at a data rate of 25 Gbit/s OOK with an extinction ratio of 6.25 dB. We also proposed a mathematically-analysed streamlined IMDD PAM-4 scheme and successfully demonstrated a 25 Gbit/s datarate PAM-4 with the same 2 mm modulator. A Michelson interferometer carrier-depletion modulator with 0.5 mm phase shift length has also been shown with modulation efficiency (V-pi.L-pi) of 1.36 V.cm at 4 V reverse bias and data rate of 20 Gbit/s 00K. The Michelson interferometer modulator performs similarly to a Mach-Zehndcr modulator with twice the phase shifter length. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.