Demonstration of the AlInAsSb cascaded multiplier avalanche photodiode

By utilizing the low-noise benefits of staircase avalanche photodiodes (APDs) and the high-field tolerance of conventional APDs, a “cascaded multiplier” device has been grown and characterized showing significantly reduced excess noise compared to k ∼ 0 materials. Because it can withstand higher electric fields than a pure staircase APD, the gain values are not limited by the number of staircase steps in the device, and higher gains are demonstrated. In addition, the cascaded multiplier device shows reduced dark current to staircase devices of similar gain. Slight adjustments to the device design could increase the gain to even higher values—further improving the signal-to-noise ratio in the detector.