Optimized High Speed UTC Photodiode for 100 Gbit/s Applications

In this paper we present an optimized high-speed uni-traveling carrier photo-diode (UTC PD) for 100 Gbit/s applications. The designed photodiode operates at 1.55 μm wavelength with a 3 dB bandwidth exceeding 110 GHz, a dark current of 1 nA at −2 V and a peak saturation current of about 30 mA at −2 V. A 40% bandwidth improvement is achieved by employing new optimized transmission lines (TMLs) to equalize the intrinsic response of the detector. In addition, results of the tested UTC, using 100 Gbit/s NRZ modulation format show considerably improved eye quality.