Single photonics at telecom wavelengths using nanowire superconducting detectors

A 16-channel fiber array-coupled superconducting single-photon detector array with average system detection efficiency over 60% at telecom wavelength

We report a compact, scalable, and high-performance superconducting nanowire single-photon detector (SNSPD) array by using a multichannel optical fiber array-coupled configuration. For single pixels with an active area of 18 um in diameter and illuminated at the telecom wavelength of 1550 nm, we achieved a pixel yield of 13/16 on one chip, an average system detection efficiency of 69% at a dark count rate of 160 cps, a minimum timing jitter of 74 ps, and a maximum count rate of ~40 Mcps. The optical crosstalk coefficient between adjacent channels is better than -60 dB. The performance of the f…

Lithium-Niobate-on-Insulator Waveguide-Integrated Superconducting Nanowire Single-Photon Detectors

We demonstrate waveguide-integrated superconducting nanowire single-photon detectors on thin-film lithium niobate (LN). Using a 250 um-long NbN superconducting nanowire lithographically defined on top of a 125 um-long LN nanowaveguide, on-chip detection efficiency of 46% is realized with simultaneous high performance in dark count rate and timing jitter. As LN possesses high second-order nonlinear \c{hi}(2) and electro-optic properties, an efficient single-photon detector on thin-film LN opens up the possibility to construct small scale fully-integrated quantum photonic chip which includes sin…

Resolving photon numbers using a superconducting tapered nanowire detector

Time- and number-resolved photon detection is crucial for photonic quantum information processing. Existing photon-number-resolving (PNR) detectors usually have limited timing and dark-count performance or require complex fabrication and operation. Here we demonstrate a PNR detector at telecommunication wavelengths based on a single superconducting nanowire with an integrated impedance-matching taper. The prototyping device was able to resolve up to five absorbed photons and had 16.1 ps timing jitter, <2 c.p.s. device dark count rate, $\sim$86 ns reset time, and 5.6% system detection efficienc…

A Multi-Layer Three Dimensional Superconducting Nanowire Photon Detector

Here we propose a new design paradigm for a superconducting nanowire single photon detector that uses a multi-layer architecture that places the electric leads beneath the nanowires. This allows for a very large number of detector elements, which we will call pixels in analogy to a conventional CCD camera, to be placed in close proximity. This leads to significantly better photon number resolution than current single and multi-nanowire meanders, while maintaining similar detection areas. We discuss the reset time of the pixels and how the design can be modified to avoid the latching failure se…

Potential of a Superconducting Photon Counter for Heterodyne Detection at Telecommunication Wavelength

Here, we report on successful operation of a NbN thin film superconducting nanowire single-photon detector (SNSPD) in a coherent mode (as a mixer) at the telecommunication wavelength of 1550 nm. Providing the Local Oscillator power of the order of a few picowatts, we were practically able to reach the quantum noise limited sensitivity. The intermediate frequency gain bandwidth was limited by the spectral band of single-photon response pulse of the detector, which is proportional to the detector size. We observed gain bandwidth of 65 MHz and 140 MHz for 7x7 um^2 and 3x3 um^2 devices respectivel…

利用单低抖动超导纳米线探测器的超高分辨率定时实现光子数分辨

Resolving Photon Numbers Using Ultra-High-Resolution Timing of a Single Low-Jitter Superconducting Nanowire Detector

本文通过对常规超导纳米线单光子探测器产生的电脉冲进行超高分辨率时间标记，实现了光子数分辨能力，该方法兼具高探测效率与高重复率，并在电信C波段通过相干光统计及非经典态相关性验证了其有效性。

Coherent Diffraction Imaging of Single 95nm Nanowires

Photonic or electronic confinement effects in nanostructures become significant when one of their dimension is in the 5-300 nm range. Improving their development requires the ability to study their structure - shape, strain field, interdiffusion maps - using novel techniques. We have used coherent diffraction imaging to record the 3-dimensionnal scattered intensity of single silicon nanowires with a lateral size smaller than 100 nm. We show that this intensity can be used to recover the hexagonal shape of the nanowire with a 28nm resolution. The article also discusses limits of the method in t…