Study of Low Power Degenerate Four-Wave Mixing in Disperse Yellow Dye-Doped Polymer Film

Abstract

Nonlinear optical phase conjugation by degenerate four-wave mixing (DFWM) is an important technique with applications in many fields of science and technology including image transmission, optical image processing, optical filtering, and laser resonators. In optimum condition, when two counter-propagating and intense light beams interact with a nonlinear medium, together with a less intense third beam, a fourth beam is generated from the medium, which will be the phase conjugation of the third beam. This technique is called four-wave mixing. In this paper, the optical phase conjugation property of disperse yellow (DY-7) dye-doped polymer films is studied using degenerate four-wave mixing method and the dependence of phase conjugated signal reflectivity on various parameters viz., dye concentration, the intensity of backward pump, forward pump, and inter-beam angle between the probe and forward pump beam on phase conjugation reflectivity are studied and presented using a low power continuous wave laser at 532 nm wavelength.

Keywords: Nonlinear optical materials, Dye-doped polymer films, Optical phase conjugation