1.064-μm-band Up-conversion Single-photon Detector

Abstract

Based on the technique of periodically poled lithium niobate (PPLN) waveguide, up-conversion single-photon detection at 1.064-μm is demonstrated. We have achieved a system photon detection efficiency (DE) of 32.5% with a very low noise count rate (NCR) of 45 counts per second (cps) by pumping with a 1.55-μm-band single frequency laser using the long-wavelength pumping technique and exploiting volume Bragg grating (VBG) as a narrow band filter. Replacing the VBG with a combination of adequate dielectric filters, a DE of up to 38% with a NCR of 700 cps is achieved, making the overall system more stable and practical. The up-conversion single-photon detector (SPD) operating at 1.064 μm can be a promising robust counter and find usage in many fields.

Non-line-of-sight imaging with picosecond temporal resolution

“…Compared with a superconducting nanowire single-photon detector having a picosecond temporal resolution [39], our detector works at room temperature without the need for cryogenic devices. A low noise counts rate of 5 cps is realized by long-wavelength-pumping [33,40] and time-gating [41] methods. With this UCSPD as the core detection device, we demonstrate a 180 µm axial resolution and a 2 mm lateral resolution capability for NLOS imaging.…”