Spectral compression of single-photon-level laser pulse

TL;DR

This paper demonstrates a method to significantly compress the bandwidth of single-photon laser pulses using a PPLN waveguide, enabling better integration of quantum communication and memory systems.

Contribution

The study introduces a novel spectral compression technique for single photons using sum-frequency generation in a PPLN waveguide, achieving a bandwidth reduction by a factor of 58.

Findings

Bandwidth of single-photon pulses compressed by factor of 58

Simultaneous frequency and bandwidth conversion at 1550 nm

Advances coherent photonic interface for quantum communication and memory

Abstract

We experimentally demonstrate that the bandwidth of single photons laser pulse is compressed by a factor of 58 in a periodically poled lithium niobate (PPLN) waveguide chip. A chirped single photons laser pulse and an oppositely chirped classical laser pulse are employed to produce a narrowband single photon pulse with new frequency through sum-frequency generation. In our experiment, the frequency and bandwidth of single photons at 1550 nm are simultaneously converted. Our results mark a critical step towards the realization of coherent photonic interface between quantum communication at 1550 nm and quantum memory in the near-visible window.