اندازه گيري ضرايب نوري غير خطي شيشه هاي چلكاجنيد به روش جاروب Z - و روش تركيب چهار موج تبهگن DFWM

Measurements of non-linear optical constants of chalcogenide glasses using Z-scan and the degenerate four wave mixing (DFWM) techniques

Chalcogenide glasses such as arseic sulfide(As 2 S 3) have attracted attention for applications such as all-optical switching in high speed communication. This is due to their high non-linear refractive-index. Z-scan and the Degenerate four wave mixing (DFWM) techniques can be used to measure the non-linear refractive index n2 and the two photon absorption coefficient beta . A simaltanous closed-aperture and open-aperture Z-scan experimental set up was used to obtain the experimental results. The results were then fitted into a theoretical formula. Values of n2= 3 * 10^-17 m^2/W and beta= 0.29 cm/GW have been obtained. DFWM measurements were made on arsenic sulfide films. A Box-cars forward geometry was used in these measurements. Experimental results based on non-phase matched signals were again fitted into a theoretical formula and a value of n 2 = 3.9 *10^-17 m^ 2 /W was obtained.