Fluctuations Electromagnetic Fields Interacting Coherently Prepared Atomic Media

Author(s)

Luciano Soares da Cruz

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
• Defense date: 2005-07-28

Examining board members

Paulo Alberto Nussenzveig; Luis Eduardo Evangelista de Araujo; Arnaldo Gammal; Antonio Zelaquett Khoury; Mario Jose de Oliveira

• Advisor: Paulo Alberto Nussenzveig

Abstract

We present a theoretical and experimental investigation of the fluctuations of electromagnetic fields after the interaction with degenerate two-level atomic systems. These atomic systems were prepared in coherent superpositions of the states obtained through Electromagnetically Induced Transparency (EIT) and Absorption (EIA). The physical system was studied in two semi-classical models: linear atomic response and phase diffusion. These models are based on the fact that diode lasers have excess phase noise, which in the interaction process is transferred to intensity noise. We observed non trivial results about the noise signals and the correlations between the fields. We showed that, in atomic vapor, the Doppler width has a fundamental role in the origin of the noise signal. The theoretical models show good qualitative agreement with part of the experimental result features and are a powerful tool to analyze field fluctuations, when the laser has excess phase noise. (AU)