25 Gbps × four-channel chip-scale optical receiver operating at up to 85 °c with a temperature-compensation function

Abstract

We successfully developed a 5 × 5 mm2 chip-scale optical receiver using silicon photonics technology. The optical receiver was integrated with a 28 nm CMOS transimpedance-amplifier chip designed to have a temperature-compensation function to achieve stable operation at high temperatures. Error-free operations were demonstrated for signals of the 25 Gbps pseudorandom binary sequence 231 - 1 at 25 °C and 85 °C using the compensation function. The minimum sensitivities and transimpedance gains were -9.5 dBm and 76.6 dB Ω at 25 °C, and -8.9 dBm and 76.7 dB Ω at 85 °C, respectively. We also verified the uniform characteristics of the four channels of the receiver with a sensitivity variation of 0.2 dB. These stable operations at a high temperature, and the uniform characteristics of the four channels indicate that our receiver can be used for 100 Gbps (25 Gbps × four-channel) applications at high temperatures.