We have demonstrated upconversion detection at the single photon level in the 2 μm spectral window using a pump wavelength near 1550 nm, 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 μm single photon detection technologies. This detector has potential applications in environmental gas monitoring, life science, and classical and quantum communication.
© 2013 Optical Society of America
Original Manuscript: September 4, 2013
Revised Manuscript: October 24, 2013
Manuscript Accepted: October 24, 2013
Published: November 21, 2013
Guo-Liang Shentu, Xiu-Xiu Xia, Qi-Chao Sun, Jason S. Pelc, M. M. Fejer, Qiang Zhang, and Jian-Wei Pan, "Upconversion detection near 2 μm at the single photon level," Opt. Lett. 38, 4985-4987 (2013)