Switchable detector array scheme to reduce the effect of single-photon detector's deadtime in a multi-bit/photon...

Area of Science:

• Quantum communication
• Photonics
• Optical engineering

Background:

• Detector deadtime limits photon detection rates in quantum communication systems.
• Orbital-angular-momentum (OAM) states offer a method for multi-bit/photon data encoding.
• Efficient single-photon detection is crucial for high-performance quantum links.

Purpose of the Study:

• To investigate a switchable single-photon detector (SPD) array scheme for reducing deadtime effects.
• To enhance the photon detection rate in multi-bit/photon quantum links utilizing OAM states.
• To analyze the performance of the proposed scheme using Monte Carlo simulations.

Main Methods:

• Implementation of a switchable SPD array with a controllable M x N optical switch.
• Utilizing a Monte Carlo-based method to simulate the quantum detection process.
• Evaluating system performance under various parameters including OAM states (M), SPD count (N), detector deadtime, and average photon number per pulse.

Main Results:

• The switchable SPD array allows a substantially higher incident photon rate compared to non-switchable configurations.
• For M=4, N=20, and 50-ns deadtime, the system supports 2250 Mcts/s, a 25-fold increase over a non-switchable 4-SPD array.
• The observed rate increase exceeds the simple ratio of SPDs to OAM states, demonstrating the scheme's effectiveness.

Conclusions:

• The switchable SPD array scheme effectively overcomes detector deadtime limitations in quantum links.
• This approach significantly enhances the achievable photon incident rates for OAM-based quantum communication.
• The proposed method offers a practical solution for improving the throughput of quantum communication systems.