Ultrahigh-sensitivity high-linearity photodetection system using a low-gain avalanche photodiode with an ultralow-noise readout circuit

Experimental Determination of the Gain Distribution of an Avalanche Photodiode at Low Gains

A measurement system for determining the gain distributions of avalanche photodiodes (APDs) in a low gain range is presented. The system is based on an ultralow-noise charge--sensitive amplifier and detects the output carriers from an APD. The noise of the charge--sensitive amplifier is as low as 4.2 electrons at a sampling rate of 200 Hz. The gain distribution of a commercial Si APD with low average gains are presented, demonstrating the McIntyre theory in the low gain range.

Efficient and Continuous Microwave Photodetection in Hybrid Cavity-Semiconductor Nanowire Double Quantum Dot Diodes

Single photon detectors are key for time-correlated photon counting applications [1] and enable a host of emerging optical quantum information technologies [2]. So far, the leading approach for continuous and efficient single-photon detection in the optical domain has been based on semiconductor photodiodes [3]. However, there is a paucity of efficient and continuous single-photon detectors in the microwave regime, because photon energies are four to five orders of magnitude lower therein and conventional photodiodes do not have that sensitivity. Here we tackle this gap and demonstrate how iti…

A multipixel silicon APD with ultralow dark count rate at liquid nitrogen temperature

The dark count rate of a multipixel photon counter (MPPC) was reduced to less than 0.2 cps by cooling the counter to 78.5 K. Characteristics of the MPPC other than the dark count rate were also detemined at 78.5 K and 295 K. The photodetection efficiency and the timing jitter at 78.5 K were comparable to those at 295 K. The MPPC had a count rate of up to 50 MHz at 78.5 K and above 100 MHz at 295 K. Detailed measurements were performed for detemining the afterpulse probability.

高灵敏度微波光子探测：腔耦合双量子点实现单腔光子灵敏度

High-efficiency microwave photodetection by cavity coupled double dots with single cavity-photon sensitivity

本文提出一种超导腔耦合双量子点光电二极管，实现25%的光电转换效率，可探测低至100 aW的微波信号并具备单光子灵敏度，为微波光子统计和量子信息处理提供关键进展。

Quantum Trajectories for Realistic Photodetection II: Application and Analysis

In the preceding paper [Warszawski and Wiseman] we presented a general formalism for determining the state of a quantum system conditional on the output of a realistic detector, including effects such as a finite bandwidth and electronic noise. We applied this theory to two sorts of photodetectors: avalanche photodiodes and photoreceivers. In this paper we present simulations of these realistic quantum trajectories for a cavity QED scenario in order to ascertain how the conditioned state varies from that obtained with perfect detection. Large differences are found, and this is manifest in the …

Quantum Trajectories for Realistic Photodetection I: General Formalism

Quantum trajectories describe the stochastic evolution of an open quantum system conditioned on continuous monitoring of its output, such as by an ideal photodetector. In practice an experimenter has access to an output filtered through various electronic devices, rather than the microscopic states of the detector. This introduces several imperfections into the measurement process, of which only inefficiency has previously been incorporated into quantum trajectory theory. However, all electronic devices have finite bandwidths, and the consequent delay in conveying the output signal to the obse…