Quantum state engineering of light with continuous-wave optical parametric oscillators

TL;DR

This paper discusses the reliable generation of non-Gaussian quantum states of light, such as single-photon states and superpositions, using optical parametric oscillators with high fidelity and mode control, essential for quantum technologies.

Contribution

It introduces a method for generating high-fidelity non-Gaussian states from optical parametric oscillators with detailed procedures for state preparation and characterization.

Findings

Successful generation of non-Gaussian states with high fidelity

Effective frequency filtering and homodyne characterization techniques

Controlled spatiotemporal mode of generated states

Abstract

The ability to engineer the quantum state of traveling optical fields is a central requirement for quantum information science and technology, including quantum communication, computing and metrology. In this video article, we describe the reliable generation of non-Gaussian states, including single-photon states and coherent state superpositions, using a conditional preparation method operated on the non-classical light emitted by optical parametric oscillators. Type-I and type-II phase-matched OPOs operated below threshold, i.e. single-mode or two-mode squeezed vacuum sources, are considered and common procedures, such as the required frequency filtering or the high-efficiency quantum state characterization by homodyning, are detailed. The reported method enables a high fidelity with the targeted state and the generation of the state in a well-controlled spatiotemporal mode, a crucial feature for their use in subsequent protocols.