Third-order Optical Nonlinearities of Singlewall Carbon Nanotubes for Nonlinear Transmission Limiting Application

Highly untangled multiwalled carbon nanotube@polyhedral oligomeric silsesquioxane ionic hybrids: Synthesis, characterization and nonlinear optical properties

“…The resulting v (3) value for poly-imi-POSS@c-MWCNT (2.38AE10 À7 esu) is higher than the one (2.67AE10 À8 esu) estimated for the poly-imi@c-MWCNT and compares fairly well with those already reported [62,63].…”

Nonlinear optical characteristics of nanocomposites of ZnO–TiO2–SiO2

“…Since n 2 increases with absorption, thermal nonlinearity is also taken into account. It is reported that if the thermal contributions are to dominate, then there will be increase in n 2 with increase of absorption [20].The third-order nonlinear susceptibility of silica nanoaerogels is estimated to be 9.6 Â 10 À19 m 2 /V 2 (6.9 Â 10 À11 esu) from FWM measurements [19]. In the case of fused silica, the nonlinear refractive index is reported to be quite small, roughly 3 Â 10 À20 m 2 /W, which is about two-order of magnitude below the nonlinear refractive index of most of the materials usually studied with the z scan method [18].…”

“…We suggest that the possible physical origin of the nonlinear refraction of ZnO-TiO 2 -SiO 2 nanocomposites is mainly a two photon absorption process and partially nonlinear scattering and a weak thermal effects in the nanosecond time domain. It is reported that the difference between the third-order optical susceptibilities for z scan and four wave mixing (FWM) is due to scattering from the surface of silica nanoaerogels in the z scan measurements [19]. We have not observed any sign reversal of the nonlinear refractive index either in the intensity ranges (150-400 MW/cm 2 ) studied using the second harmonics of a Q-switched Nd:YAG laser or within the wavelength range 450-650 nm studied using a tunable laser (Quanta Ray MOPO, 5 ns, 10 Hz).…”

“…The nonlinear refractive index increases substantially in the nanocomposites, as compared to pure SiO 2 colloids. The large enhancement of the third-order nonlinearity of the silica aerogel is reported to be due to the quantum confinement effect of bound electrons, which is induced by the nanostructure nature of the sample [19]. Since n 2 increases with absorption, thermal nonlinearity is also taken into account.…”

Theoretical Studies of Substitutionally Doped Single-Walled Nanotubes

“…Over the past 20 years, research efforts have aimed to improve both efficiency and selectivity of nanotube synthesis, as well as understand their chemical reactivity and extraordinary electronic and thermal properties [3][4][5]. Carbon nanotubes have significant potential for application in molecular electronics [6][7][8][9][10][11][12][13][14][15], nanomechanics [16][17][18][19][20], optics [21][22][23][24], sensors [6,[25][26][27][28][29][30][31], and even catalysis [32].…”