Free-Running Single-Photon Detection via GHz Gated InGaAs/InP APD for High Time Resolution and Count Rate up to 500...

Area of Science:

• Photonics and Optoelectronics
• Semiconductor Devices
• Quantum Optics

Background:

• Free-running InGaAs/InP single-photon avalanche photodiodes (SPADs) in active-quenching mode suffer from long dead times and significant timing jitter.
• Existing SPADs often require synchronous gating, limiting their application in free-running detection scenarios.

Purpose of the Study:

• To demonstrate a 1-GHz gated InGaAs/InP SPAD capable of free-running single-photon detection using asynchronous sinusoidal gating.
• To investigate and mitigate the factors contributing to timing jitter in such devices.
• To evaluate the performance of the developed SPAD under varying operational conditions.

Main Methods:

• Implementation of a 1-GHz gated InGaAs/InP SPAD with asynchronous sinusoidal gating signals relative to the incident pulsed laser.
• Avalanche signal quenching within 1 ns to minimize dead time.
• Systematic adjustment of the delay between gating signals and laser pulses to analyze timing jitter.
• Investigation of the impact of incident laser power and operating temperature on time resolution.

Main Results:

• Achieved a count rate of up to 500 Mcount/s with significantly reduced dead time (<1 ns).
• Measured timing jitter of approximately 168 ps, which is higher than synchronous SPADs.
• Identified the causes of timing jitter deterioration through delay adjustments and analyzed its dependence on laser power and temperature.

Conclusions:

• The developed 1-GHz gated free-running SPAD offers high count rates and reduced dead time, expanding its applicability.
• Further optimization is needed to address the observed timing jitter for enhanced time resolution.
• The device shows potential for applications in laser ranging, imaging, fluorescence spectroscopy, and optical time-domain reflectometry.