Interfacing picosecond and nanosecond quantum light pulses

TL;DR

This paper presents a method to coherently compress the spectral bandwidth of quantum light pulses, bridging the gap between picosecond and nanosecond quantum information processing platforms, enabling large-scale hybrid quantum systems.

Contribution

It introduces a large-aperture time lens using high-bandwidth electro-optic modulation for efficient spectral bandwidth compression of quantum pulses.

Findings

Achieved spectral bandwidth compression of quantum light pulses by over two orders of magnitude.

Demonstrated coherent and deterministic spectral compression with high efficiency.

Facilitates integration of ultrafast and nanosecond quantum information platforms.

Abstract

Light is a key information carrier, enabling worldwide high-speed data transmission through a telecommunication fibre network. This information-carrying capacity can be extended to transmitting quantum information (QI) by encoding it in single photons -- flying qubits. However, various QI-processing platforms operate at vastly different timescales. QI-processing units in atomic media, operating within nanosecond to microsecond timescales, and high-speed quantum communication, at picosecond timescales, cannot be efficiently linked due to orders of magnitude mismatch in the timescales or, correspondingly, spectral linewidths. In this work, we develop a large-aperture time lens using complex high-bandwidth electro-optic phase modulation to bridge this gap. We demonstrate coherent, deterministic spectral bandwidth compression of quantum light pulses by more than two orders of magnitude with high efficiency. It will facilitate large-scale hybrid QI-processing by linking the ultrafast and quasi-continuous-wave experimental platforms, which until now, to a large extent, have been developing independently.