Single photon MIR upconversion detector at room temperature with a PPLN ridge waveguide.

Area of Science:

• Photonics and Optical Engineering
• Quantum Optics
• Infrared Technology

Background:

• Mid-infrared (mid-IR) light detection is crucial for various applications, including spectroscopy and sensing.
• Achieving high-performance single-photon detection in the mid-IR at room temperature remains a significant challenge.
• Existing technologies often require cryogenic cooling or lack efficiency.

Purpose of the Study:

• To demonstrate a novel upconversion detector capable of single-photon detection in the mid-infrared (around 3.5 μm).
• To leverage periodically poled lithium niobate (PPLN) ridge waveguide technology for enhanced detection capabilities.
• To achieve room-temperature operation without compromising performance.

Main Methods:

• Fabrication of a PPLN ridge waveguide designed for mid-IR wavelengths.
• Implementation of an upconversion scheme to convert mid-IR photons to a detectable shorter wavelength.
• Characterization of the detector's performance, including detection efficiency, dark count rate, and noise equivalent power.

Main Results:

• Successful single-photon detection at room temperature in the mid-IR (3.5 μm).
• Achieved a detection efficiency of 0.4% with a dark count rate of 22k counts per second at 192 mW pump power.
• Obtained a noise equivalent power of 3.0 fW·Hz^-1/2 and an internal conversion efficiency of 85%/W of pump power.

Conclusions:

• The developed PPLN ridge waveguide upconversion detector offers a promising solution for mid-IR single-photon detection at room temperature.
• This technology has the potential to advance applications in fields requiring sensitive mid-IR measurements.
• The results highlight the efficacy of integrated photonics for enhancing optical detector performance.