Broadband chip-based source of a quantum noise with electrically-controllable beam splitter

TL;DR

This paper presents a novel broadband quantum noise generator using an integrated lithium niobate Mach-Zehnder interferometer with electrically controllable beam splitting, achieving record noise excess over classical levels.

Contribution

It introduces a practical, integrated optical beam splitter for broadband quantum noise generation with electro-optical balancing, demonstrating superior noise excess performance.

Findings

Achieved 12 dB quantum noise excess over classical noise.

Operates effectively over a frequency band exceeding 4 GHz.

First demonstration of a broadband quantum noise generator with integrated optics.

Abstract

For the first time, the theory and practical realization of a broadband quantum noise generator based on original integrated optical beam splitter in the form of a Mach-Zehnder interferometer is demonstrated. The beam splitter with a double output, made on a lithium niobate substrate, provided accurate electro-optical balancing of the homodyne quantum noise detection circuit. According to our knowledge, the experimentally obtained excess of quantum noise over classical noise by 12 dB in the frequency band over 4 GHz, which is the best parameters of quantum noise generators known from the literature.