Detection of squeezing by on-chip glass-integrated homodyne analyzer

TL;DR

This paper presents an on-chip homodyne detection device fabricated via femtosecond laser micromachining, capable of detecting nonclassical features like squeezing in quantum states.

Contribution

It introduces a fully integrated glass-based homodyne analyzer with on-chip beam splitter and phase shifter for quantum state tomography.

Findings

Successful detection of squeezed states

On-chip device performs reliable quantum state tomography

Demonstrates nonclassical feature detection in integrated photonics

Abstract

We design and demonstrate on-chip homodyne detection operating in the quantum regime, i.e. able to detect genuine nonclassical features. Our setup exploits a glass-integrated homodyne analyzer (IHA) entirely fabricated by femtosecond laser micromachining. The IHA incorporates on the same chip a balanced waveguide beam splitter and a thermo-optic phase shifter, allowing us to record homodyne traces at different phases and to perform reliable quantum state tomography. In particular, we show that the IHA allows for the detection of nonclassical features of continuous-variable quantum states, such as squeezed states.