Ultrafast uni-traveling carrier photodiode

The evolution of photonics technology has dramatically increased the speed of signal processing systems. As signal speeds increase, ultrafast photodetectors with high saturation power levels become more important for applications such as high-bit-rate fiber-optic communications (Miyamoto et al., 1998) and ultrafast measurement (Nagatsuma et al., 1994). This is because a combination of a high-saturation-power photodiode with an optical fiber amplifier can eliminate the post-amplification electronics, extend the bandwidth, and thus simplify the receiver configuration. The uni-traveling-carrier photodiode (UTC-PD) (Ishibashi et al, Tech. Dig. UEO, p. 166, 1997), which has a unique mode of operation, is a promising candidate for such requirements. In this paper, we describe recent progress in our UTC-PD technologies.