Infrared single photon detector based on optical up-converter at 1550 nm

Area of Science:

• Optoelectronics
• Quantum Information Science

Background:

• Single photon detectors are crucial for quantum information and quantum key distribution.
• Detectors operating at 1550 nm are vital for fiber optic communication and quantum technologies.
• Existing detectors face challenges with dark count rates and afterpulsing.

Purpose of the Study:

• To propose and characterize a novel infrared up-conversion single photon detector (USPD) for the 1550 nm telecom band.
• To demonstrate suppression of dark count rate and afterpulsing without compromising photon detection efficiency (PDE).
• To provide a new detection scheme for single photon detection in the telecom wavelength range.

Main Methods:

• Development of a USPD system utilizing an InGaAs/InP photodetector, GaAs/AlGaAs LED up-converter, and a Silicon single photon avalanche diode (SPAD).
• Optical adhesive coupling to enhance light transfer between the up-converter and the Si SPAD.
• Application of a developed analytical model to determine noise equivalent power (NEP).

Main Results:

• Achieved a high photon detection efficiency (PDE) of approximately 45% through optimized optical coupling.
• Demonstrated efficient suppression of dark count rate and afterpulsing compared to conventional InGaAs SPADs.
• Calculated a noise equivalent power (NEP) of 1.39 × 10⁻¹⁸ WHz¹/² at 200 K, outperforming InGaAs SPADs.

Conclusions:

• The novel USPD offers a promising new scheme for single photon detection at 1550 nm.
• The USPD exhibits superior performance characteristics, including reduced noise and afterpulsing.
• This technology has significant potential for applications in quantum information and secure communication.