InGaAs/AlGaAsSb Avalanche Photodiodes with sub 100fW/√Hz noise equivlent power at 22 to 52 °C

Separate - Absorption - Multiplication Avalanche Photodiode (SAM-APD) made from Al0.85Ga0.15As0.56Sb0.44 (AlGaAsSb) avalanche region and InGaAs absorption region exhibits low dark current, excess noise, and Noise Equivalent Power (NEP) at room temperature. However, its performance at elevated temperatures has not been reported. In this work we performed comprehensive measurements of dark current, avalanche gain and noise spectrum of three InGaAs/AlGaAsSb SAM-APDs at 22 to 52∘C. We observed a weak temperature dependence of dark current and breakdown voltage has a temperature coefficient of 12.9(±0.5)mV/∘C, which is 6−15 times better than a number of commercial 1550 nm APD modules. The best NEP ranges between 78 and 92fW/√Hz at 22 to 52° C with NEP at 52° C outperforming a number of commercial 1550 nm APD modules at 22∘C. The low NEP value enable the InGaAs/AlGaAsSb SAM-APDs to detect optical pulse with as few as 78 photons per pulse at 22∘C, increasing to 100 photons at 52∘C. These results demonstrate that InGaAs/AlGaAsSb SAMAPDs have a superior temperature tolerance to maintain gain, NEP and low photon detection compared to typical 1550 nm SAMAPDs. Therefore, they can potentially increase the range and sensitivity of gas sensing, free space optical communication and ranging instruments.