RESUMEN
The nonlinear response of silica--gold nanoshells (SGNs) in chloroform was studied using laser pulses of 65 fs at 1560 nm. The experiments were performed using the thermally managed Z--scan technique that allows measurements of the electronic contribution for the nonlinear response, free from thermal influence. The results were analyzed using an analytical approach based on the quasi--static approximation that allowed extraction of the nonlinear susceptibility of a SGN from the data. High third--order susceptibility, χsh((3)) = - 1.5 x 10(-11) m(2)/V(2), approximately four orders of magnitude larger than for gold nanospheres in the visible, and large fifth--order susceptibility, χsh((5)) = - 1.4 x 10(-24) m(4)/V(4), were obtained. The present results offers new perspectives for nonlinear plasmonics in the near--infrared.
Asunto(s)
Cloroformo/química , Oro/química , Nanopartículas del Metal/química , Nanotecnología/métodos , Dióxido de Silicio/química , Algoritmos , Electrones , Calor , Microscopía Electrónica/métodos , Microscopía Electrónica de Rastreo/métodos , Microscopía Electrónica de Transmisión/métodos , Modelos Estadísticos , Óptica y Fotónica , Fotones , Resonancia por Plasmón de SuperficieRESUMEN
Closed form expressions for the high harmonic generation (HHG) conversion efficiency are obtained for the plateau and cutoff regions. The presented formulas eliminate most of the computational complexity related to HHG simulations, and enable a detailed scaling analysis of HHG efficiency as a function of drive laser parameters and material properties. Moreover, in the total absence of any fitting procedure, the results show excellent agreement with experimental data reported in the literature. Thus, this paper opens new pathways for the global optimization problem of extreme ultraviolet (EUV) sources based on HHG.
Asunto(s)
Óptica y Fotónica , Simulación por Computador , Análisis de Fourier , Gases , Rayos Láser , Modelos Estadísticos , Modelos Teóricos , Neón , Distribución Normal , Fibras Ópticas , Programas Informáticos , Rayos UltravioletaRESUMEN
We present a 9 GW peak power, three-cycle, 2.2 microm optical parametric chirped-pulse amplification source with 1.5% rms energy and 150 mrad carrier envelope phase fluctuations. These characteristics, in addition to excellent beam, wavefront, and pulse quality, make the source suitable for long-wavelength-driven high-harmonic generation. High stability is achieved by careful optimization of superfluorescence suppression, enabling energy scaling.
RESUMEN
Carrier-envelope (CE) phase-stabilized sub-two-cycle pulses are generated from a 500 MHz compact prismless octave-spanning laser without extracavity nonlinear optical processes distorting the laser output. The necessary f and 2f spectral components are generated intracavity and coupled out independently from the main pulse through specially designed cavity mirrors, resulting in a 55 dB CE beat note (100 kHz resolution bandwidth). The in-loop CE phase error (integrated from 2.5 mHz to 10 MHz) is 67 mrad, equivalent to a timing jitter between carrier and envelope of 28 as at 790 nm.