Progress in Quenching Circuits for Single Photon Avalanche Diodes

Abstract

Abstract—An ever wider variety of applications employ Single\ud Photon Avalanche Diodes (SPADs) for the detection of faint optical\ud signals. SPADs are p-n junction biased above the breakdown\ud voltage and operate in Geiger-mode: each electron-hole pair can\ud trigger an avalanche multiplication process that causes the current\ud to swiftly rise to its final value. Additional quenching electronics\ud is necessary for a SPAD proper working. The additional\ud electronics characteristics directly affect the system’s obtainable\ud performances. Different quenching circuits affect the detector performances\ud in different ways. In the last 15 years there has been\ud considerable development in the integration of the quenching circuitry\ud directly with the detector, thus leading to improved performances.\ud This paper reviews the state of the art of this evolution,\ud examining and comparing different classes of quenching circuits\ud and explaining their mode of operations, their advantages and disadvantages

Improved Circuits for Single-photon Avalanche Photodiode Detectors

“…6)). To compare the response of the proposed circuits with the conventional circuit, the dead time was initially adjusted to 400 ns which is the dead time of conventional passive quenching circuit [5]. In terms of the reset time (rising time), the proposed circuits (both R and C types) show the improvement of at least 100 ns.…”

“…The long reset time causes a long dead time leading to single photon detection errors. To overcome this drawback, active type quenching circuit has been introduced [5]. The quenching and reset operations are implemented using active circuit components (active quenching).…”

“…The active quenching time is faster than that of passive quenching, though the actual time of the active quenching is not still small enough. The time that takes to restore its original state depends on various factors, such as SPAD bias conditions, parasitic components including inductance from the connection between SPAD and bias quenching circuit, capacitances, and so on [5]. To reduce the quenching time further, mixed type between active and passive quenching circuits is generally preferred.…”

“…Fig. 1 shows a basic schematic of a bias quenching circuit architecture and its associated circuits for operation in Geiger mode [5]. When no current flows, the reverse bias across the APD equals to V DD + V OP (=V DD + |V OP |).…”

Single photon avalanche detectors: prospects of new quenching and gain mechanisms

“…Passive quenching uses a resistor, traditionally external to the device, to drop the bias across the device in response to impact ionisation current [17]. Passive quenching is a frequently used means of quenching, although afterpulsing effects are an issue since the voltage across the device begins to rise immediately following quenching [18].…”