High quantum efficiency photon-number-resolving detector for photonic on-chip information processing

We demonstrate a high-efficiency, photon-number resolving transition edge sensor, integrated on an optical silica waveguide structure. The detector consists of three individual absorber/sensor devices providing a total system detection efficiency of up to 93% for single photons at a wavelength of 1551.9 nm. This new design enables high fidelity detection of quantum information processes in on-chip platforms

High-speed >90% quantum-efficiency p-i-n photodiodes with a resonance wavelength adjustable in the 795-835 nm range

We report GaAs/AlGaAs-based high-speed, high-efficiency, resonant cavity enhanced p-i-n photodiodes. The devices were fabricated by using a microwave-compatible fabrication process. By using a postprocess recess etch, we tuned the resonance wavelength from 835 to 795 nm while keeping the peak efficiencies above 90%. The maximum quantum efficiency was 92% at a resonance wavelength of 823 nm. The photodiode had an experimental setup-limited temporal response of 12 ps. When the system response is deconvolved, the 3 dB bandwidth corresponds to 50 GHz, which is in good agreement with our theoretical calculations. © 1999 American Institute of Physics

High-efficiency Bragg grating enhanced on-chip photon-number-resolving detectors

The recent trend towards integration of quantum optics experiments has produced a demand for on-chip single photon detectors with high quantum efficiencies. In previous work we demonstrated integrated photon number resolving detectors for use at telecommunications wavelengths [1], here we outline developments of this design which have enabled improvements in the quantum efficiency, permitting an on-chip detection efficiency of 92% to be obtained in the device of Fig. 1. ..

Experimental investigation of the detection mechanism in WSi nanowire superconducting single photon detectors

Quantum Matter and Optic

Single-photon source characterization with twin infrared-sensitive superconducting single-photon detectors

We report on the high fidelity characterization, via spontaneous emission lifetime and g(2)(τ) measurements, of a cavity-coupled quantum dot single-photon source at 902 nm using a pair of nanowire-based superconducting single-photon detectors (SSPDs). We analyze the suitability of the twin SSPD scheme reported here for the characterization of single-photon sources at telecommunications wavelengths (1310 and 1550 nm)

Quantum dot single photon sources studied with superconducting single photon detectors

We report the observation of photon antibunching from a single, self-assembled InGaAs quantum dot (QD) at temperatures up to 135 K. The second-order intensity correlation, <formula formulatype="inline"><tex>$g^{(2)}$</tex> </formula>(0), is less than 0.260 <formula formulatype="inline"><tex>$pm$</tex></formula> 0.024 for temperatures up to 100 K. At 120 K, <formula formulatype="inline"><tex>$g^{(2)}$</tex></formula>(0) increases to about 0.471, which is slightly less than the second-order intensity correlation expected from two independent single emitters. In addition, we characterize the performance of a superconducting single photon detector (SSPD) based on a nanopatterned niobium nitride wire that exhibits 68 <formula formulatype="inline"><tex>$pm$</tex></formula> 3-ps timing jitter and less than 100-Hz dark count rate with a detection efficiency (DE) of up to 2% at 902 nm. This detector is used to measure spontaneous emission lifetimes of semiconductor quantum wells (QWs) emitting light at wavelengths of 935 and 1245 nm. The sensitivity to wavelengths longer than 1 <formula formulatype="inline"><tex>$mu$</tex></formula>m and the Gaussian temporal response of this superconducting detector present clear advantages over the conventional detector technologies. We also use this detector to characterize the emission from a single InGaAs QD embedded in a micropillar cavity, measuring a spontaneous emission lifetime of 370 ps and a <formula formulatype="inline"><tex>$g^{(2)}$</tex> </formula>(0) of 0.24 <formula formulatype="inline"><tex>$pm$</tex></formula> 0.03

High-speed high-efficiency large-area resonant cavity enhanced p-i-n photodiodes for multimode fiber communications

The large active-area AlGaAs-GaAs p-i-n photodiodes were reported with a 3-dB bandwidth in excess of 10 GHz for devices as large as 60μmeter diameter. Resonant cavity enhanced photodetection was employed to improve the quantum efficiency. Performance of photodiodes exceeded the requirement for 10-Gb/s optical communication system. A bandwidth of more than 20 GHz was attainable for photodiodes having 50 μmeter diameter with potential for 40-Gbs application, with a factor of two reduction in the load resistance

High Power Generation of THz From 1550-NM Photoconductive Emitters

Two photoconductive emitters - one with a self-complementary square spiral antenna, and the other with a resonant slot antenna - were fabricated on a GaAs epilayer embedded with ErAs quantum dots. Driven with 1550 nm mode-locked lasers, ~117 μW broadband THz power was generated from the device with the spiral antenna, and ~1.2 μW from the device with resonant slot antenna. The optical-to-THz conversion is through extrinsic photoconductivity