Studying the quantum state of the field at the threshold of the optical parametric oscillator

• Grant number: 17/27216-4
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): April 01, 2018
• Effective date (End): February 28, 2021
• Field of knowledge: Physical Sciences and Mathematics - Physics
• Principal Investigator: Marcelo Martinelli
• Grantee: Alvaro Montaña Guerrero
• Home Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 15/18834-0 - Exploring quantum information with atoms, crystals and chips, AP.TEM

Abstract

Optical Parametric Oscillators (OPO) are a versatile source of non-classical gaussian states of light. They are a widely used tool for experiments in quantum information in the continuous variable domain. Their operation both above and below threshold are widely studied and well know. Nevertheless, the transition from the generation of thermal entangled states (below threshold) to intense entangled field (above threshold), and the non-Gaussian behavior that is expected to happen under this transition are limited by the narrow range of pump powers for which such effects can be observed in usual conditions, with closed optical cavities and nonlinear crystals as a gain medium. We propose the study of OPOs using atomic nonlinearities of the third order. Due to they high parametric gain, we can deal with open cavities, showing a soft transition. This will allow the investigation of the evolution of the output state while the operation regime is changes under the increasing pump power. Moreover, their low threshold power allows the investigation of operation regimes well above the threshold power, that were not investigated yet even for OPOs using second order nonlinearity.The generation of non-classical, non-Gaussian states, gives an interesting tool for the investigation of entanglement beyond the gaussian regime, which shows limitation for the application in quantum information. (AU)