A High-Speed Grating-Assistant SOA-PIN Photodetector With High Sensitivity

With an increased demand for high speed and high sensitivity in optical communication system applications, semiconductor optical amplifier (SOA)-PIN photodetectors and AlInAsSb, InGaAs/InAlAs, or Ge/Si based avalanche photodiodes (APDs) have attracted extensive attentions. Nevertheless, their gain-bandwidth products and sensitivities are limited either by the amplified spontaneous emission (ASE) noise of the SOA or by the long avalanche buildup time in the avalanche multiplication process. In this paper, we have proposed a grating-assistant SOA-PIN photodetector (GA-SOA-PIN) aiming at raising its sensitivity by filtering out the ASE noise. Our simulation result shows that it can achieve a sensitivity close to −25 dBm under a transmission data rate of 100 Gbps at 1.55 μm with a bit error rate (BER) of 10
⁻¹²
. With a simulated gain-bandwidth product reaches 2.62 THz, for systems with their data rates beyond 40 Gbps, the performance of the proposed GA-SOA-PIN is superior as compared to that achievable by the best available APD and SOA-PIN photodetectors.