Excess noise factor measurement for low-noise high-speed avalanche photodiodes

Abstract

Abstract The excess noise factor(F) is an important parameter for Avalanche Photodiodes (APDs), indicating the extent to which the noise of the diodes exceeds what it would be without multiplication. This paper presents a method of measuring the excess noise factor for high-speed low-noise APDs using the high-sensitivity spectrum analyzer. The F factor test for the high-speed low-noise APDs was performed by comparing two conditions with and without illumination to remove the interference of the system, including the thermal noise and analyzers. The setup conditions of the light source are analyzed in detail. The F factor was obtained as 3.03 when the multiplication factor M is 10, which corresponds to an effective ionization coefficient ratio k of 0.14 for the high-speed InAlAs APD. For comparison, the k value of a commercial Si APD is tested to be ∼0.06.