Construction and Characterization of an Avalanche Photodiode Detector*

Traditional photodetectors built using photodiodes are relatively inexpensive, robust, and have high quantum efficiencies, but their responsivity is small. Photomultiplier tubes have much higher responsivities due to electron avalanche multiplication, but have lower quantum efficiency, are more expensive, and fragile. Avalanche photodiodes have many of the advantages of standard photodiodes, but also utilize electron avalanche multiplication.  We are working on constructing a small, precise, and inexpensive avalanche photodiode detector utilizing modern voltage converter and amplifier chips. This detector would use a commercially available avalanche photodiode instead of a regular photodiode to achieve a higher internal gain while maintaining a large quantum efficiency to allow more accurate measurements of low intensity light.