"

Cookies ussage consent

Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our site without changing the browser settings you grant us permission to store that information on your device.

Angle-resolved evanescent-wave cavity ring-down spectroscopy for thin film-solid interface characterization

C. COTIRLAN1, C. LOGOFATU1, A. RIZEA2, M. F. LAZARESCU1,*

Affiliation

  1. National Institute of Materials Physics, P.O.Box MG-7, RO-077125 Magurele, Romania
  2. ProOptica S.A., 67, Gh.Petrascu St., RO-745081, Bucharest, Romania

Abstract

A new method, that involves Evanescent-Wave Cavity Ring-Down Spectroscopy (EW-CRDS), is presented. This method is useful for the study of thin films on optical solid surfaces. The new design of experimental set-up incorporates a semicylindrical prism with a plane surface where the Total Internal Reflection (TIR) effect appears. The antireflex (AR) coated cylindrical surface of the prism induces the stability of resonant cavity. The evanescent wave generated at the plane surface of the prism probes the absorption by matter in the vicinity of the prism. A general discussion of design criteria is presented to quantify intrinsic losses, and then absorption spectra for Rhodamine chloride R590 from 555 to 560 nm are presented to demonstrate the sensitivity of the system. The layer of R590 on BK7 surfaces is deposited from a solution of R590 in ethanol (92% purity) with 51 mg/l concentration. After vaporization of the ethanol the dye layer on surfaces is supposed to be uniform. This implementation of TIR surface in a resonant cavity provides a powerful new spectroscopic tool especially to angle-resolved diagnostic for interfaces and thin-films. The loss spectrum can be obtained for an angular range from the TIR critical angle to a maximum angle when the resonance of system is lost..

Keywords

Cavity Ring-Down Spectroscopy (CRDS), Evanescent Wave (EW), Total Internal Reflection (TIR), Thin film-solid interface.

Citation

C. COTIRLAN, C. LOGOFATU, A. RIZEA, M. F. LAZARESCU, Angle-resolved evanescent-wave cavity ring-down spectroscopy for thin film-solid interface characterization, Optoelectronics and Advanced Materials - Rapid Communications, 5, 7, July 2011, pp.709-714 (2011).

Submitted at: June 17, 2011

Accepted at: July 25, 2011