Cascaded frequency upconversion for high-speed single-photon detection at 1550 nm.

Area of Science:

• Quantum optics and photonics
• Optical engineering
• Solid-state physics

Background:

• Single-photon detection is crucial for quantum information processing and sensitive measurements.
• Existing methods for frequency conversion often suffer from low efficiency and high noise.
• Detection of telecom-band single photons requires specialized, low-timing-jitter detectors.

Purpose of the Study:

• To develop a device for efficient two-stage frequency upconversion of single-photon signals.
• To enable detection of telecom-band photons by readily available silicon single-photon avalanche photodiodes (APDs).
• To achieve low excess noise and low timing jitter in the upconversion process.

Main Methods:

• Implementation of a two-stage frequency upconversion process for 1.55 μm telecom signals.
• Utilizing components optimized for low excess noise operation.
• Characterization of the system's conversion efficiency and timing jitter performance.

Main Results:

• Achieved a net conversion efficiency of 87% from the telecom band to the green spectral region.
• Demonstrated a system timing jitter below 70 picoseconds Full Width at Half Maximum (FWHM).
• The timing jitter was primarily limited by the performance of the silicon single-photon avalanche photodiodes (APDs).

Conclusions:

• The developed device offers a highly efficient and low-noise solution for upconverting telecom single photons.
• The system is compatible with low-timing-jitter silicon single-photon avalanche photodiodes (APDs).
• Device modifications can also facilitate downconversion of visible photons to the telecom band for quantum applications.