Articles you may be interested inTime-gated single-photon detection module with 110 ps transition time and up to 80 MHz repetition rate Rev. Sci. Instrum. 85, 083114 (2014); 10.1063/1.4893385 Two-bit quantum random number generator based on photon-number-resolving detection Rev. Sci. Instrum. 82, 073109 (2011); 10.1063/1.3613952 Efficient photon number detection with silicon avalanche photodiodes Appl. Phys. Lett. 97, 031102 (2010); 10.1063/1.3464556Single-photon detection using a quantum dot optically gated field-effect transistor with high internal quantum efficiency Appl.

We demonstrate an efficient photon number detector for visible wavelengths using a silicon avalanche photodiode. Under subnanosecond gating, the device is able to resolve up to four photons in an incident optical pulse. The detection efficiency at 600 nm is measured to be 73.8%, corresponding to an avalanche probability of 91.1% of the absorbed photons, with a dark count probability below 1.1x10^{-6} per gate. With this performance and operation close to room temperature, fast-gated silicon avalanche photodiodes are ideal for optical quantum information processing that requires single-shot photon number detection

Low-noise single-photon detection is a prerequisite for quantum information processing using photonic qubits. In particular, detectors that are able to accurately resolve the number of photons in an incident light pulse will find application in functions such as quantum teleportation and linear optics quantum computing. more generally, such a detector will allow the advantages of quantum light detection to be extended to stronger optical signals, permitting optical measurements limited only by fluctuations in the photon number of the source. Here we demonstrate a practical high-speed device, which allows the signals arising from multiple photon-induced avalanches to be precisely discriminated. We use a type of silicon avalanche photodiode in which the lateral electric field profile is strongly modulated in order to realize a spatially multiplexed detector. Clearly discerned multiphoton signals are obtained by applying sub-nanosecond voltage gates in order to restrict the detector current.

We demonstrate the use of two high speed avalanche photodiodes in exploring higher order photon correlations. By employing the photon number resolving capability of the photodiodes the response to higher order photon coincidences can be measured. As an example we show experimentally the sensitivity to higher order correlations for three types of photon sources with distinct photon statistics. This higher order correlation technique could be used as a low cost and compact tool for quantifying the degree of correlation of photon sources employed in quantum information science.

We demonstrate an efficient photon number detector for visible wavelengths using a silicon avalanche photodiode. Under sub-nanosecond gating, the device is able to resolve up to four photons in an incident optical pulse. The detection efficiency at 600 nm is measured to be 73.8%, corresponding to an avalanche probability of 91.1% of the absorbed photons, with a dark count probability below 1.1 × 10 −6 per gate. With this performance and operation close to room temperature, fast-gated silicon avalanche photodiodes are ideal for optical quantum information processing that requires single-shot photon number detection. Many applications require low-level light detection, such as biomedical imaging, time-of-flight ranging, astronomy and scientific research. In particular, highly efficient and low noise single photon detectors are a prerequisite for quantum information processing based on photonic qubits. 1 For some advanced functions, these detectors must be able to resolve the number of photons in an optical pulse. [2][3][4] For over a decade, silicon avalanche photodiodes 5,6 (Si-APD) have been the detector of choice for single photon detection at visible wavelengths due to their practicality, high quantum efficiency (QE) and low dark count noise. Their spectral response also makes them compatible with a number of quantum light sources. 7 However, Si-APDs are believed to be threshold devices that detect only the presence or absence of photons, but not the photon number. Multiplexing in temporal 8 or spatial domain 9-11 can be used to approximate a photon number detector (PND), but these devices suffer from cross-talk, high dark count rates as well as reduced efficiency due to the geometrical fill-factor. Alternative technologies, such as visible light photon counters 12,13 or transition edge sensors, 14 are capable of efficient PND, but the requirement of cryogenic cooling limits their prospect for practical use.For single photon detection, APDs are usually biased with a dc voltage above their breakdown, such that a single photo-excited carrier can stimulate a macroscopic current by means of avalanche multiplication. In this Geiger-mode, the avalanche is allowed to develop to a level that saturates the device, resulting in high detection efficiencies but a current that is independent of the number of photons initiating the avalanche. Recently, a practical scheme for PND has been demonstrated for InGaAs APDs operating at telecom wavelengths. 15 This is implemented by gating the device with sub-nanosecond voltage pulses, 16 which are sufficiently short so as for photoinduced avalanches not to saturate the device. However, these APDs are insensitive to photons at wavelengths that are currently most commonly used for wider applications in applied physics.To bridge this gap, we demonstrate here an efficient PND using a fast-gated Si-APD. Operating close to room temperature we obtain a detection efficiency of 73.8%, giving an avalanche detection probability of 91.1% for absorbed photons. The device is able to resolve aval...