We demonstrated a laser ranging system with single photon detection at 1550 nm. The single-photon detector was 1-GHz sine-wave gated InGaAs/InP avalanche photodiode. In daylight, 8-cm depth resolution achieved directly by using time-of-flight approach based on time-correlated counting measurement. This presented potential for low energy level and eye-safe in long-range

We demonstrated a time-of-flight (TOF) ranging system employing laser pulses at 1550 nm with multiple repetition rates to decrease the range ambiguity, which was usually found in high-repetition TOF systems. The time-correlated single-photon counting technique an InGaAs/InP avalanche photodiode based detector, applied record different arrival time of scattered return photons from non-cooperative target determine measured distance, providing effective and convenient method increase absolute...

In this paper, we present a method for measuring weak light pulses using single-photon detector, with focus on detecting non-synchronized repetitive pulsed light. The proposed approach, based interval distribution counting, enables accurate reconstruction of both the repetition rate and phase pulses, facilitating determination average photon number pulse width. Specifically, error in reconstructing is below ±0.01%, while per remains ±0.8%.

Polarization feedback control of single-photon pulses has been achieved in long-distance fibers for more than 10 hours, which facilitated "one-way" polarization-encoded quantum key distribution with long-term stabilities. Experimental test polarization encoding 75 km demonstrated that the transformation could be controlled to provide a typical QBER (3.9+/-1.5)% within operation 620 minutes.

We demonstrate an efficient way to improve the timing jitter of sine-wave gated InGaAs/InP avalanche photo diode (APD) by combining sinusoidally balanced differencing and low-pass filtering techniques minimize detrimental waveform distortion signal, realize a 1-GHz single-photon detector with as low 60 ps. The detection efficiency could reach 10.4% at 1550 nm maximum count rate ~100 MHz, after pulse probability ~3.0%, dark ~6.1 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...

The ability to achieve precise underwater 3D imaging is an urgent need in marine research and development. Yet, due the strong scattering by water, laser beam easily spread out propagation, which hampers quality with low resolution. In this paper, we demonstrate a single-photon LiDAR Bessel illumination, central spot shows stable diameter of about 0.73 mm after propagating 18 m water. Together detector sense weak returning echoes, transverse resolution reaches few millimeters at 17.5...

An efficient single-photon detector at telecom wavelength of 1.55 μm was realized with an InGaAs/InP avalanche photodiode −30 °C. By implementing a short gating pulse and optimizing the self-differencing circuit, detection efficiency 29.3% achieved error count probability 6% frequency 200 MHz, paving way for high-efficiency low-noise fast infrared single photons.

Sensitive laser ranging was demonstrated at few-photon level using photon-number-resolving (PNR) detectors. The reflected photon pulses from a non-cooperation remote target were distinguished in sunlight environment of 2.5×103 lx by setting the discrimination threshold 5-photon level. By comparing detected numbers, two targets with different reflection coefficients well recognized. PNR detection facilitated sensitivity similar capabilities linear optical This technique avoids photon-counting...

Many range-free localization algorithms estimate the distance in between two nodes based on hop-count information, which, however, is a coarse proximity measure. Recently, regulated neighborhood (RND) has been proposed as new measure, and can greatly improve accuracy, compared with those hop-count-based algorithms. However, RND algorithm most previous hop-based approaches are disk communication model, cannot be directly applied into practical world some general radio propagation model. In...

In this letter, we report the experimental demonstration of a single-photon router based on time-division Sagnac interferometer, wherein differential phase shifts are applied either clockwise or counterclockwise quasi-single-photon pulses to determine single photon interference and consequently output routing. High fidelity (&amp;gt;85%) routing was demonstrated over long-distance loop. Stable performance guaranteed by passive compensation stress temperature dependent drifts fiber-optic...

By using a self-differencing circuit to achieve efficient spike cancellation for the near-infrared single-photon detector based on InGaAs/InP avalanche photodiode, we verified that shortening gate duration enforced detection efficiency saturate at an increased voltage, while increasing gain favored discrimination of signals caused by different photon-number states. Photon-number resolving was realized measuring weak current built-up. The performance could be improved gating pulse duration.

A low-noise high-speed InGaAs/InP-based single-photon detector was demonstrated with a double-self-differencing spike signal cancellation technique. photon-number resolving method used to analyze the ratio of avalanche background noise. By adding post-self-differencing circuit pre-self-differencing circuit, noise improved by 11.0 dB. The typical error count probability as low 2.1% and 6.4% at detection efficiency 20.6% 30.5%, respectively.

We demonstrate a high-speed photon-number-resolving detector based on sinusoidally gated multipixel photon counter (MPPC) at repetition rate of 200 MHz. Two steps low-pass filters are used to minimize the MPPC's capacitive response noise in Geiger mode, resulting efficient detection weak photon-induced avalanche currents. Compared with passive quenching schemes, sinusoidal gating scheme is conducive shortening recovery time for each pixel MPPC detect next coming photons, thus improving...

We report on the sensitive detection of photons at broadband infrared wavelengths based nondegenerate two-photon absorption in Si avalanche photodiodes. The detected 1700~1850 nm photon energy is lower than band gap and difference complemented by a high intensity pump laser field 1550 nm. It thus possible to capitalize low noise property large materials for detecting photons. And linear response detector incident was observed when power about 12.42μ W, indicating dominance detection. An...

We report on a high-speed temporal and spatial multiplexed single-photon counter with photon-number-resolving capability up to four photons. The infrared detector combines fiber loop split, delay recombine optical pulses 200 MHz dual-channel based InGaAs/InP avalanche photodiode. To fully characterize the capability, we perform quantum tomography then reconstruct its positive-operator-valued measure associated Wigner functions. result shows that, despite of afterpulsing noise limited system...

A free-space communication scheme is proposed based on orbital angular momentum (OAM) states and pulse position modulation (PPM). It can not only improve the channel capacity, but also be suitable for single-photon detection to realize in case of ultra-weak light. parallel coding method high-capacity low bit error rate (BER) under high background. Theoretical simulation experimental results show that effectively suppress background noise. The BER as 1.27 × 10 <inline-formula...

We demonstrate a portable system integrated with time comparison, absolute distance ranging, and optical communication (TRC) to meet the requirements of space gravitational wave detection. A 1 km free-space asynchronous two-way link is performed. The TRC realizes 7.7×10-5 bit error rate Si avalanche photodiode single-photon detector, while signal intensity 1.4 photons per pulse background noise 3×104 counts second. measurement uncertainty 48.3 mm, comparison precision 162.4 ps. In this...

With recent development of nanotechnology, novel devices with nanostructures arise to improve the performance photodetectors. Here, we demonstrated that by surface decoration gold nanoparticles on active area, quantum detection efficiency a multi-pixel photon counter was increased due plasmon resonance enhancement. The deposited nano-particles actually brought about almost same enhancement factor for any photon-number fields. As result, photon-number-resolving capability well reserved...

Gamma-ray ( γ -ray) radiation for silicon single photon avalanche diodes (Si SPADs) is evaluated, with total dose of 100 krad(Si) and rate 50 rad(Si)/s by using 60 Co as the -ray source. The breakdown voltage, photocurrent, gain have no obvious change after radiation. However, both leakage current dark count increase about one order magnitude above values before Temperature-dependent current–voltage measurement results indicate that traps caused function generation recombination centers....