High-ON/OFF-contrast 10-Gb/s silicon Mach-zehnder modulator in high-speed low-loss package

10-Gb/s silicon-based Mach-Zehnder modulator is packaged and characterized. The I/O sections of the modulator chip are located at longer-facet sides using bends waveguides for enhancing modulation bandwidth by using short straight configuration of traveling-wave electrodes. Low-insertion loss and high-return-loss optical coupling structure between input/output lenses and the modulator chip is achieved with optical coupling, where both of chip facets and inverted-taper mode-field-convertors are angled with respect to incident light beam. 3-dB electro-optic bandwidth is as high as 12.0-GHz and optical insertion loss is 9-dB or lower. High-contrast eye diagram with an extinction ratio of 13.8-dB is obtained.