Abstract

We report on extremely low excess noise in AlAs0.56Sb0.44 lattice matched to InP. The deduced β/α ratio as low as 0.005 in the avalanche region of 1550 nm is close the theoretical minimum and is significantly smaller than even in Silicon, offering the potential of realizing vertically illuminated APDs with a sensitivity of -25.7dBm at a BER = 1×10-12 for 25 Gb/s operation at 1550 nm.