Abstract:
<jats:p>We have combined the reflection and transmission Z-scan (RZ- and TZ-scans) techniques under femtosecond laser at 800nm to extract both the third- and fifth-order nonlinear refractive indices (n2 and n4) in InN thin films. The observation of the nonlinear refractive index saturation in the intensity-dependent RZ-scan measurement indicates the existence of the fifth-order effect. By the aid of the TZ-scan, the fifth-order nonlinear effect has been enhanced by enlarging the cascaded contribution from the increased laser interaction length, where large n2 of −2.5×10−11cm2∕W and n4 of 2.1×10−19cm4∕W2 have been determined.</jats:p>
Description:
<jats:p>We have combined the reflection and transmission Z-scan (RZ- and TZ-scans) techniques under femtosecond laser at 800nm to extract both the third- and fifth-order nonlinear refractive indices (n2 and n4) in InN thin films. The observation of the nonlinear refractive index saturation in the intensity-dependent RZ-scan measurement indicates the existence of the fifth-order effect. By the aid of the TZ-scan, the fifth-order nonlinear effect has been enhanced by enlarging the cascaded contribution from the increased laser interaction length, where large n2 of −2.5×10−11cm2∕W and n4 of 2.1×10−19cm4∕W2 have been determined.</jats:p>