# Streak-camera measurements of single photons at telecom wavelength

## TL;DR

This paper introduces a method to enable streak-camera measurements of single photons at telecom wavelengths by using up-conversion in Lithium Niobate waveguides, overcoming previous infrared signal-to-noise limitations.

## Contribution

The authors demonstrate a novel up-conversion technique that allows streak-cameras to effectively measure single photons in the telecom range, expanding their applicability.

## Key findings

- Successful up-conversion of telecom photons to visible wavelengths
- Enhanced detection efficiency with commercially available streak-cameras
- Analysis of phase-matching configurations for optimal conversion

## Abstract

Up to this point streak-cameras have been a powerful tool for temporal characterization of ultrafast light pulses even at the single photon level. However, the low signal-to-noise ratio in the infrared range prevents measurement on weak light sources in the telecom regime. We present an approach to circumvent this problem. The method utilizes an up-conversion process in periodically poled waveguides in Lithium Niobate. We convert single photons from a parametric down-conversion source in order to reach the point of maximum detection efficiency of commercially available streak-cameras. We explore phase-matching configurations to investigate the up-conversion scheme in real-world applications.