50-GHz bandwidth, 0.75-A/W, optoelectronic stimulus probe head employing multimode waveguide p-i-n photodiode

We developed a highly efficient, broad-band optoelectronic stimulus probe head employing a 1.55-μm waveguide p-i-n photodiode (WGPD). The novel multimode waveguide structure of the WGPD and optical lens-based rigid coupling assembly yielded a very high responsivity of 0.75 A/W. The OE probe has an effective 3-dB bandwidth of 50 GHz which is currently limited by the frequency dispersion of the CPW used in the probe, 2-mW, 64-Gb/s RZ optical pulse patterns were successfully able to be converted to 200 mVpp electrical pulses.