# Quantum temporal imaging: application of a time lens to quantum optics

## TL;DR

This paper explores the use of a temporal imaging system with a time lens in quantum optics, focusing on preserving quantum features like squeezing during temporal manipulation.

## Contribution

It analyzes the restrictions on pump and phase matching in quantum temporal imaging, highlighting the narrower quantum field of view compared to classical systems.

## Key findings

- Quantum field of view is significantly narrower than classical.
- Proper phase matching is crucial for preserving quantum features.
- Temporal imaging can be applied to quantum-enhanced metrology and communications.

## Abstract

We consider application of a temporal imaging system, based on the sum-frequency generation, to a nonclassical, in particular, squeezed optical temporal waveform. We analyze the restrictions on the pump and the phase matching condition in the summing crystal, necessary for preserving the quantum features of the initial waveform. We show that modification of the notion of the field of view in the quantum case is necessary, and that the quantum field of view is much narrower than the classical one for the same temporal imaging system. These results are important for temporal stretching and compressing of squeezed fields, used in quantum-enhanced metrology and quantum communications.