Efficient single-photon counting at 1.55 um via frequency upconversion

Wong, Marius A. Albotǎ, Shapiro

Imogen Morland, Ruaridh Smith, Jack W. Thomas +8 more

Wenjie Wu, Jianhui Ma, Haifeng Pan +4 more

Guo-Liang Shentu, Xiu-Xiu Xia, Qi-Chao Sun +4 more

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.

Huang, Gu, Ren +4 more

Huafang Dong, Haifeng Pan, Yao Li +2 more

We demonstrated an efficient single-photon frequency upconversion system for the infrared photons at 1.06 μm with ultralow background counts. By pumping the system at a longer wavelength than that of the single-photon signal, the background counts caused by the pump-induced parametric fluorescence in the nonlinear crystal were reduced markedly. We achieved so far the lowest noise of ∼150/s for a near unity conversion efficiency.