Investigating the influence of ITO thin film thickness on the optical Kerr nonlinearity using ultrashort laser pulses

Abstract

In this paper, we present results from the measurements of the optical Kerr nonlinearity of indium tin oxide (ITO) thin films of different thicknesses using the femtosecond (fs) Z-scan technique. ITO thin films were prepared by radio frequency magnetron sputtering on a glass substrate at room temperature. The coated ITO thin films were subsequently characterized by UV–visible absorption spectroscopy, x-ray diffraction, and scanning electron microscopy. Using ∼ 100 f s pulses at 80 MHz repetition rate, the optical Kerr nonlinearity in ITO with different thicknesses was investigated at different excitation wavelengths and incident pulse energies. The optical Kerr nonlinearity was found to be dependent on excitation wavelength, incident power, and ITO thickness, with a maximum value of ∼ 9 × 1 0 − 12 c m 2 / W at a wavelength of 820 nm, power of 1 W, and 170 nm ITO thickness. These results suggest that Kerr nonlinearity in ITO can be tailored by varying the film thickness, which would be ideal for ultrafast all-optical switching in future optoelectronic devices.

Boosting optical nonlinearity in epsilon-near-zero trilayer coatings

“…A Z-scan thermal effect model can be used to exclude the thermal effects from the calculation of the nonlinear coefficients of the samples. 18 High repetition rate laser pulses cause an increase in the temperature of the sample and conduct heat radially outward from the center of the incidence point. This radial temperature gradient leads to a thermal lens effect.…”

Variation of Nonlinear Refraction and Three-Photon Absorption of Indium–Tin Oxide Quantum Dot Thin Films and Solutions in Near Infrared Range

“…The measured nonlinear refractive index was found to be dependent on a wavelength with a maximum value of 5 × 10 −12 cm 2 W −1 at the wavelength of 900 nm. Recently, the influence of ITO thin-film thickness on the optical Kerr nonlinearity using ultrashort laser pulses was reported [ 12 ]. The effect of crystallinity on the nonlinear optical properties of ITO thin films was analyzed in [ 13 ].…”