(Invited) Improved Avalanche Photodiodes for Long Wavelength Optical Fiber Systems

Abstract

This paper reviens Ge-APDs and InGaAs/InP-APDs with improved properties for long wavelength fiber systems. Ge-APDs with p+-n and n+-n-p junction structures have lower multiplication noise in the wavelength region of 1–1.55 µm than that of a conventional n+-p structure Ge-APD. InGaAs/InP-APDs with separated absorption and multiplication regions have lower dark current and lower multiplication noise in the 1–1.6 µm wavelength region than those of Ge-APDs. This APD has a capability to improve the minimum detectable power by 3–4 dB, compared with Ge-APD.