Photoinduced refractive index variation within picosecond laser pulses excitation as the indicator of oxyorthosilicates single crystals composition modification

Abstract

For the first time, the diagnostics of oxyorthosilicates single crystals based on self-action of picosecond range laser pulses at 1,064 nm (1.17 eV) has been performed. High sensitivity of the photoinduced refractive index variation to the substitution of the Lu atoms by Gd in the LSO/LGSO crystalline host as well as to the admixture of Ce was found. The effect can be explained with different electron detrapping-recombination process efficiencies due to the resonant electron excitation from the deep traps in the gap attributed to intrinsic oxygen vacancies.

Application of P(VDF-TrFE) Glass Coating for Robust Harmonic Nanoparticles Characterization

“…At these levels of excitation intensity, the influence of NLO effects based on self-action of laser beam cannot be neglected. In order to analyze NLO properties of polymer, the technique based on spatial profile analysis via laser beam self-action [ 44 ] was used. Figure 3 shows the photoinduced variations of total and on-axis transmittance versus the peak laser intensity for the studied P(VDF-TrFE) samples with different thickness—one of the significant parameters for coating.…”

“…In general in our work the obtained magnitudes |Re ( χ (3) )|~10 −8 esu of self-action effect manifestation at wavelength 1064 nm corresponded to the reference data, where the sign and the magnitude of Re( χ (3) ) depended on the dopant type and its concentration. The opposite signs of the refractive NLO response can be attributed to the difference in excitation regimes concerning (i) laser wavelength [ 53 ], (ii) pulsed (ns vs. ps) or CW mode [ 54 ], and (iii) range of the applied peak laser intensities [ 44 ].…”

“…Designing of novel coatings for nonlinear optical applications requires precise characterization for working excitation intensity range. For this purpose a laser beam self-action analysis technique [ 42 , 43 , 44 , 45 ] was used (see Figure 1 a). For measurements, Nd:YAG-based laser (1064 nm, FWHM 42 ps, repetition rate 40 Hz, Institute of Physics, National Academy of Science of Ukraine, Kyiv, Ukraine) was applied.…”

Impact of Water Adsorption on Nonlinear Optical Properties of Functionalized Porous Silicon

“…The NLO response due to the self-action of the picosecond range laser pulses at 1064 nm (42 ps FWHM, repetition rate 50 Hz) in the samples was studied within the laser beam spatial profile analysis in the far field [9]. The proposed method was successfully applied for the porous silicon NLO response studies [6].…”

“…Each curve corresponds to the ∼5000 registered laser shots. The detailed models for the cubic NLO susceptibility ( χ (3) ) calculation from the experimental data are given in [9]. The real part characterizes the photoinduced variations of the refractive index Δn ∼Re( χ (3) ) I within the peak laser intensity I .…”