High-performance evanescently-coupled uni-traveling-carrier photodiodes

A new evanescently-coupled uni-traveling-carrier photodiode (EC-UTC PD) based on a multimode diluted waveguide (MDW) structure is fabricated, analysed and characterized. Optical and electrical characteristics of the device are investigated. The excellent characteristics are demonstrated such as a responsivity of 0.36 A/W, a bandwidth of 11.5 GHz and a small-signal 1-dB compression current greater than 18 mA at 10 GHz. The saturation current is significantly improved compared with those of similar evanescently-coupled pin photodiodes. The radio frequency (RF) bandwidth can be further improved by eliminating RF losses induced by the cables, the probe and the bias tee between the photodiode and the spectrum analyzer.

National High Technology Research and Development of China 2006AA01Z256 2007AA03Z419 2007AA03Z417 State Key Development Program for Basic Research of China 2006CB604901 2006CB604902 National Natural Science Foundation of China 90401025 607360366070600960777021Project supported by the National High Technology Research and Development of China (Grant Nos 2006AA01Z256, 2007AA03Z419 and 2007AA03Z417), the State Key Development Program for Basic Research of China (Grant Nos 2006CB604901 and 2006CB604902), and the National Natural Science Foundation of China (Grant Nos 90401025, 60736036, 60706009 and 60777021).