Real‐time dark count compensation and temperature monitoring using dual SPADs on the same chip. Issue 10 (1st May 2018)

• Record Type: Journal Article
• Authors: Deng, Shijie; Morrison, Alan P.
• Is Part Of: Electronics letters. Volume 54:Issue 10(2018)
• Page Start: 642
• Page End: 643
• Publication Date: 2018-05-01
• Subjects: avalanche photodiodes -- photon counting -- photodetectors -- temperature sensors -- integrated optoelectronics -- integrated optics; dual SPADs -- dual single‐photon avalanche photodiodes -- real‐time monitoring -- chip temperature -- identical active quench -- similar DCR performance -- bias voltages -- normally operated SPAD -- shaded SPAD -- sensor chip -- counting rate -- real‐time dark count compensation -- temperature monitoring -- dark count rate compensation -- integrated circuits -- incident light power; Electronics -- Periodicals; 621.381
• DOI: 10.1049/el.2018.0341
• Languages: English
• ISSNs: 0013-5194

Abstract

Abstract : Dual single‐photon avalanche photodiodes (SPADs) integrated on the same chip enable the effective compensation of dark count rate (DCR) in the SPAD and also the real‐time monitoring of the chip temperature. In the design, two identical SPADs are fabricated on the same chip, one operating normally and the other one covered by a metal layer to be kept in the dark. The two SPADs are identically biased and connected to identical active quench and reset integrated circuits. As both detectors are identical in structure, the dark count is expected to be similar for both. Experimental measurements show that the two SPADs exhibit similar DCR performance over a range of bias voltages and temperatures. By measuring the DCR from the covered SPAD, the DCR from the normally operated SPAD can be accounted for directly. This can be particularly useful for SPADs, where the DCR is high. Experiments under illumination show that the shaded SPAD is immune to illumination over a wide range of incident light power. This enables the real‐time monitoring of the temperature on the sensor chip using the counting rate from the dark operated avalanche photodiode (APD).