A High-Linearity Avalanche Photodiodes With a Dual-Carrier Injection Structure

This letter presents a novel avalanche photodiode (APD) featuring a unique absorber that provides high-linearity operation. Different from conventional APDs, this APD has an absorber at both sides of the avalanche layer. This configuration effectively suppresses hole accumulation and the space-charge effect in the absorber. The fabricated APD exhibits an improved 1-dB compression point corresponding to an input power of -6.3 dBm at a gain of 10. It was found that its excess-noise characteristics are comparable to those of conventional electron-injection type and InAlAs APDs even though the new APD operates according to a dual-carrier injection and multiplication principle.