A Compact and Highly Efficient Silicon-Based Asymmetric Mach–Zehnder Modulator with Broadband Spectral Operation

An asymmetric Mach–Zehnder electro-optic modulator is demonstrated by using a silicon-based p-i-n diode embedded in compact 200 µm long phase shifters. The measured figure of merit V_πL=0.23 V⋅mm shows highly efficient modulation by the device, and an open eye−diagram at 3.2 Gbit/s confirmed its fast electro-optic response. Integrated with the grating coupler, the device exhibits a broad operational wavelength range of 70 nm with a uniform 18 dB extinction ratio covering the C−band and part L-band of optical communication.