A 2.0 μm cutoff wavelength separate absorption, charge, and multiplication layer avalanche photodiode using strain-compensated InGaAs quantum wells

We report an avalanche photodiode structure for use at wavelengths as long as 2.1 μm. Light is absorbed in a 100 period structure consisting of In0.83Ga0.17As quantum wells strain compensated by In0.83Ga0.17P barrier layers. Photogenerated electrons are injected into a high field In0.52Al0.48As (ionization rate ratio=0.2) gain region initiating low noise avalanche multiplication. Primary dark currents of ∼5 nA and responsivities of 45 A/W at a wavelength of 1.9 μm are observed.