title: Thermo-optic effect and optical third order nonlinearity in nc-Si embedded in a silicon-nitride film.
abstract: Using a self-diffraction experiment with 7ns pulses at 532nm we studied a silicon nitride film containing silicon nanoclusters (nc-Si) of 3.1+/-0.37 nm mean size. The sample was prepared by remote plasma-enhanced chemical vapor deposition (RPECVD), and we found that its nonlinearity consists of a combination of electronic and thermal contributions. By varying the repetition rate of the laser, we discriminated the responsible mechanisms for the nonlinear response. Using this procedure we determined a total /chi((3))1111/ = 3.3x10(-10)esu, n2 = 2.7x10(-16) m(2)/W, beta = 1x10(-9) m/W and dn/dT =1x10(-4) degrees C(-1) for our sample. We also show results for the optical Kerr effect using 80 fs pulses at 820 nm. The purely electronic nonlinearity measured is characterized by /chi((3))1111/=9.5 x10(-11) esu.
authors.affiliation: Sección de Estudios de Posgrado e Investigación-ESIME-IPN, Zacatenco, México DF, México. crstorres@yahoo.com.mx
authors.forename: C
authors.initials: C
authors.lastname: Torres-Torres
authors.forename: A
authors.initials: A
authors.lastname: López-Suárez
authors.forename: L
authors.initials: L
authors.lastname: Tamayo-Rivera
authors.forename: R
authors.initials: R
authors.lastname: Rangel-Rojo
authors.forename: A
authors.initials: A
authors.lastname: Crespo-Sosa
authors.forename: J C
authors.initials: JC
authors.lastname: Alonso
authors.forename: A
authors.initials: A
authors.lastname: Oliver