Aberration-corrected quantum temporal imaging system

TL;DR

This paper presents a quantum temporal imaging system that corrects phase distortions using a field lens, enabling precise reshaping and frequency conversion of quantum photonic wavepackets for quantum information applications.

Contribution

It introduces a novel field lens correction technique for quantum temporal imaging, improving phase preservation and efficiency over traditional far-field methods.

Findings

The field lens removes residual phase with four dispersive elements.

The system achieves temporal imaging of time-bin entangled photons.

Dispersion requirements are optimized for quantum applications.

Abstract

We describe the design of a temporal imaging system that simultaneously reshapes the temporal profile and converts the frequency of a photonic wavepacket, while preserving its quantum state. A field lens, which imparts a temporal quadratic phase modulation, is used to correct for the residual phase caused by field curvature in the image, thus enabling temporal imaging for phase-sensitive quantum applications. We show how this system can be used for temporal imaging of time-bin entangled photonic wavepackets and compare the field lens correction technique to systems based on a temporal telescope and far-field imaging. The field-lens approach removes the residual phase using four dispersive elements. The group delay dispersion (GDD) $D$ is constrained by the available bandwidth $\Delta\nu$ by $D>t/\Delta\nu$, where $t$ is the temporal width of the waveform associated with the dispersion $D$. This is compared to the much larger dispersion $D\gg \pi t^2/8$ required to satisfy the Fraunhofer condition in the far field approach.