science24.com - Study of the third order nonlinear optical properties of Zn1-xMgxSe and Cd1-xMgxSe crystals

Search for content and authors

Study of the third order nonlinear optical properties of Zn_1-xMg_xSe and Cd_1-xMg_xSe crystals

Beata Derkowska ¹, Franciszek S. Firszt ¹, Bouchta Sahraoui ², Agnieszka Marasek ¹, Magdalena Kujawa ¹

1. Nicolaus Copernicus University, Institute of Physics, Grudziądzka 5/7, Toruń 87-100, Poland
2. Laboratory POMA, UMR CNRS, University of Angers, 2 Boulevard Lavoisier, Angers 49045, France

Abstract

Third order nonlinear optical susceptibilities (c⁽³⁾) of ternary Zn_1-xMg_xSe and Cd_1-xMg_xSe crystals have been measured using standard degenerate four wave mixing (DFWM) method at 532nm. The nonlinear transmission technique have been applied to check if our crystals exhibit two-photon absorption. The two-photon absorption coefficients (b), is directly related to the imaginary part of the third order nonlinear optical susceptibility at the excitation wavelength. The studied Zn_1-xMg_xSe and Cd_1-xMg_xSe solid solutions were grown from the melt by the modified high-pressure Bridgman method. For both crystals the energy gap increases with increasing Mg content.

In the case of Zn_1-xMg_xSe, we have found that the value of third order nonlinear optical susceptibility (c⁽³⁾) decreases with increasing of Mg content. An explanation of this behavior results from the dependence of optical nonlinearities on the energy band gap (E_g) of the studied crystals.

We have also found that the value of third order nonlinear optical susceptibility (c⁽³⁾) for Cd_0.64Mg_0.36Se is higher than for Zn_0.65Mg_0.35Se. This behavior can be understand if one take into consideration that the free carrier concentration in Cd_1-xMg_xSe samples is about four orders of magnitude higher than that in Zn_1-xMg_xSe ones with comparable Mg content respectively. It is commonly known that when the electric conductivity increases the values of nonlinear optical properties increase.

In the case of Cd_1-xMg_xSe with low content of Mg, no response was observed for the studied wavelength since the energy gap in such crystals is smaller than the photon energy of laser radiation.

From the performed measurements one can conclude that the incorporation of Mg as constituent into ZnSe and CdSe crystals leads to change the third order nonlinear optical susceptibilities.

Legal notice

Legal notice:

Copyright (c) Pielaszek Research, all rights reserved.
The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/9780 must be provided.