# Two-Color Bright Squeezed Vacuum

## TL;DR

This paper demonstrates the generation and direct detection of two-color bright squeezed vacuum with record twin-beam squeezing, enabling practical quantum information applications through a novel measurement approach.

## Contribution

It introduces a method for directly detecting macroscopic two-color squeezed vacuum using large detection areas and times, achieving record squeezing levels.

## Key findings

- Record twin-beam squeezing for bright squeezed vacuum.
- Direct detection of macroscopic quantum states is feasible.
- Potential for practical quantum information processing.

## Abstract

In a strongly pumped non-degenerate traveling-wave OPA, we produce two-color squeezed vacuum with up to millions of photons per pulse. Our approach to registering this macroscopic quantum state is direct detection of a large number of transverse and longitudinal modes, which is achieved by making the detection time and area much larger than the coherence time and area, respectively. Using this approach, we obtain a record value of twin-beam squeezing for direct detection of bright squeezed vacuum. This makes direct detection of macroscopic squeezed vacuum a practical tool for quantum information applications.