Upconversion single photon detection near 2 um

TL;DR

This paper demonstrates a single photon detection method near 2 um using upconversion in PPLN waveguides, achieving 10% efficiency and low noise, suitable for various scientific and communication applications.

Contribution

It introduces a novel upconversion detection technique at 2 um with improved efficiency and noise reduction using a VBG, advancing single photon detection technology.

Findings

Achieved 10% detection efficiency at 2 um

Reduced noise count rate to 24,500 cps

Demonstrated potential for environmental and quantum applications

Abstract

We have demonstrated upconversion detection at the single photon level in the 2 um spectral window using a pump wavelength near 1550nm, a periodically poled lithium niobate (PPLN) waveguide, and a volume Bragg grating (VBG) to reduce noise. We achieve a system photon detection efficiency of 10%, with a noise count rate of 24,500 counts per second, competitive with other 2 um single photon detection technologies. This detector has potential applications in environmental gas monitoring, life science, and classical and quantum communication.