Monolithic quad-cells for single-photon timing and tracking

摘要

We present the design and fabrication of 2x2 Quad-Cells and related electronics for ultra-sensitive detection and spatial tracking of single photons in the visible wavelength range. Though four pixels do not offer the imaging capabilities of CCDs, CMOS sensors and the like, their single-photon sensitivity enables most detection equipments demanding higher detection efficiency, faster gated operation, and sharper time response. In fact Quad-Cells are aimed to both photon-counting and photon-timing applications, i.e. whenever it is important to reconstruct both continuous or slow-varying very-faint light signals (with time-slots down to 50&mgr;s) and very fast luminescence waveforms (down to 150-ps), by having at the same time either the spatial information of the photon absorption position or the possibility to track the luminous source. In this paper we present the design and fabrication of 2x2 Quad-Cell, with pixel diameters from 50&mgr;m to 100 &mgr;m, developed by means of a planar microelectronic processing. They reach 55%-detection efficiency at 520-nm-wavelength and show a broad peak, higher than 40% in the 420-660-nm range, with still more than 2% at 1,000 nm.