An integrated source of broadband quadrature squeezed light

TL;DR

This paper proposes an integrated silicon nitride resonator as a compact, efficient source of broadband quadrature squeezed light at 850 nm, with potential for high squeezing levels over GHz bandwidths.

Contribution

It introduces a novel integrated waveguide design with low loss and efficient fiber coupling, enabling significant quantum noise squeezing in a compact device.

Findings

Simulated total loss of -0.75 dB/facet with the proposed design

Predicted squeezing of approximately -7 dB at 50 mW pump power

Bandwidth exceeding 1 GHz for quantum noise squeezing

Abstract

An integrated silicon nitride resonator is proposed as an ultra-compact source of bright single-mode quadrature squeezed light at 850 nm. Optical properties of the device are investigated and tailored through numerical simulations, with particular attention paid to loss associated with interfacing the device. An asymmetric double layer stack waveguide geometry with inverse vertical tapers is proposed for efficient and robust fibre-chip coupling, yielding a simulated total loss of -0.75 dB/facet. We assess the feasibility of the device through a full quantum noise analysis and derive the output squeezing spectrum for intra-cavity pump self-phase modulation. Subject to standard material loss and detection efficiencies, we find that the device holds promises for generating substantial quantum noise squeezing over a bandwidth exceeding 1 GHz. In the low-propagation loss regime, approximately -7 dB squeezing is predicted for a pump power of only 50 mW.