# Integrated transition edge sensors on lithium niobate waveguides

## TL;DR

This paper demonstrates a novel integrated system combining lithium niobate waveguides with superconducting transition edge sensors for efficient, polarization-sensitive photon detection at 1550 nm, enabling advanced quantum optics experiments.

## Contribution

It introduces the first proof-of-principle integration of transition edge sensors with lithium niobate waveguides, highlighting polarization sensitivity and photon-number resolution.

## Key findings

- Successful evanescent coupling of light to the detector
- Demonstration of polarization-dependent coupling efficiency
- Photon-number resolution capability

## Abstract

We show the proof-of-principle detection of light at 1550 nm coupled evanescently from a titanium in-diffused lithium niobate waveguide to a superconducting transition edge sensor. The coupling efficiency strongly depends on the polarization, the overlap between the evanescent field, and the detector structure. We experimentally demonstrate polarization sensitivity of this coupling as well as photon-number resolution of the integrated detector. The combination of transition edge sensors and lithium niobate waveguides can open the field for a variety of new quantum optics experiments.