Open AccessModification of the nonlinear optical absorption and optical Kerr response exhibited by nc-Si embedded in a silicon-nitride film
Author(s) -
A. López-Suárez,
C. Torres-Torres,
R. Rangel-Rojo,
JorgeAlejandro ReyesEsqueda,
G. Santana,
J. C. Alonso,
A. Ortíz,
A. Oliver
Publication year - 2009
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.17.010056
Subject(s) - materials science , nanoclusters , silicon nitride , annealing (glass) , silicon , analytical chemistry (journal) , refractive index , photoluminescence , optics , transmittance , absorbance , z scan technique , kerr effect , blueshift , optoelectronics , nonlinear optics , nanotechnology , chemistry , physics , laser , nonlinear system , chromatography , quantum mechanics , composite material
We studied the absorptive and refractive nonlinearities at 532 nm and 26 ps pulses for silicon-nitride films containing silicon nanoclusters (nc-Si) prepared by remote plasma-enhanced chemical vapor deposition (RPECVD). Using a self-diffraction technique, we measured for the as-grown sample beta=7.7x10(-9)m/W, n(2)=1.8x10(-16)m(2)/W, and /chi(3)1111/ = 4.6x10(-10)esu; meanwhile, when the sample was exposed to an annealing process at 1000 degrees C during one hour in a nitrogen atmosphere, we obtained beta=-5x10(-10)m/W, n2=9x10(-17)m(2)/W, and /chi(3)1111/=1.1x10(-10)esu. A pure electronic nonlinear refraction was identified and a large threshold ablation of 41 J/cm(-2) was found for our films. By fitting nonlinear optical transmittance measurements, we were able to estimate that the annealed sample exhibits a response time close to 1 fs. We report an enhancement in the photoluminescence (PL) signal after the annealing process, as well as a red-shift due to an increment in size of the nc-Si during the thermal process.