Creation and Measurement of Broadband Squeezed Vacuum from a Ring Optical Parametric Oscillator

TL;DR

This paper presents a broadband triangular optical parametric oscillator (OPO) capable of generating squeezed vacuum with high bandwidth and low loss, suitable for advanced quantum information processing applications.

Contribution

The development of a broadband, low-loss triangular OPO with a 65MHz bandwidth and a unique ring cavity structure for generating multiple squeezed vacua.

Findings

8.4dB squeezing at 3MHz

2.4dB squeezing at 100MHz

Suitable for high-speed quantum information processing

Abstract

We report a 65MHz-bandwidth triangular-shaped optical parametric oscillator (OPO) for squeezed vacuum generation at 860nm. The triangle structure of our OPO enables the round-trip length to reach 45mm as a ring cavity, which provides a counter circulating optical path available for introducing a probe beam or generating another squeezed vacuum. Hence our OPO is suitable for the applications in high-speed quantum information processing where two or more squeezed vacua form a complicated interferometer, like continuous-variable quantum teleportation. With a homemade, broadband and low-loss homodyne detector, a direct measurement shows 8.4dB of squeezing at 3MHz and also 2.4dB of squeezing at 100MHz.