Ultrafast optical phase modulation with metallic nanoparticles in ion-implanted bilayer silica

Abstract

The nonlinear optical response of metallic-nanoparticle-containing composites was studied with picosecond and femtosecond pulses. Two different types of nanocomposites were prepared by an ion-implantation process, one containing Au nanoparticles (NPs) and the other Ag NPs. In order to measure the optical nonlinearities, we used a picosecond self-diffraction experiment and the femtosecond time-resolved optical Kerr gate technique. In both cases, electronic polarization and saturated absorption were identified as the physical mechanisms responsible for the picosecond third-order nonlinear response for a near-resonant 532 nm excitation. In contrast, a purely electronic nonlinearity was detected at 830 nm with non-resonant 80 fs pulses. Regarding the nonlinear optical refractive behavior, the Au nanocomposite presented a self-defocusing effect, while the Ag one presented the opposite, that is, a self-focusing response. But, when evaluating the simultaneous contributions when the samples are tested as a multilayer sample (silica-Au NPs-silica-Ag NPs-silica), we were able to obtain optical phase modulation of ultra-short laser pulses, as a result of a significant optical Kerr effect present in these nanocomposites. This allowed us to implement an ultrafast all-optical phase modulator device by using a combination of two different metallic ion-implanted silica samples. This control of the optical phase is a consequence of the separate excitation of the nonlinear refracting phenomena exhibited by the separate Au and Ag nanocomposites.

Femto-, pico- and nano-second refractive nonlinearities exhibited by Au nanoparticles

“…Furthermore, the nonlinear absorption can be completely eliminated by reducing from ps to fs the pulse duration and by using a wavelength totally out of resonance. 23 Figure 4 is a typical single trace obtained with well reproducible data. Experimental results remain constant within the experimental error level, which is far below of the observed effect.…”

“…These results are in good agreement with the results previously reported. 1,23 The magnitude of the resulting nonlinear response strongly depends on the wavelength and the pulse duration of the optical irradiation. These experiments demonstrate that it is possible to nullify the thermal response by reducing from ns to ps the pulse duration, with a consequence that mainly provokes a reduction of the nonlinear absorption and a decrement in the optical susceptibility.…”

Synthesis of optical waveguides in SiO2 by silver ion implantation

“…The field includes the physics of the implantation process itself, the materials science of the optical oxides and their structure-property relationships, and also the area of modern photonics [3][4][5][6][7][8][9][10][11][12][13][14].…”

“…Furthermore, heavy ion implantation (i.e. Ag, Cu, Au) in optical materials has promising nonlinear optical properties for advanced photonic applications [6][7][8][9][10][11][12]. However, there are only a few reports of optical waveguides obtained by metal ion implantation [13][14][15].…”

Ultrasonic Influence on Plasmonic Effects Exhibited by Photoactive Bimetallic Au-Pt Nanoparticles Suspended in Ethanol

“…The NLO response of thin films and NPs suspensions has been measured by different multiphoton absorption techniques [21]. Particularly, the NLO effects seem to be enhanced by tuning the optical field [22], which has been experimentally demonstrated in a wide range of nano-optic [23], acousto-optic [24], and acousto-plasmonic interactions.…”