Enhancement of ultrafast nonlinear optical response of silicon nanocrystals by boron-doping.
Nonlinear optical responses of boron (B)-doped silicon nanocrystals (Si-ncs) embedded in borosilicate glass were studied by z-scan and optical Kerr gate methods under femtosecond excitation at 780 nm. The nonlinear refractive index (n(2)) and the two photon absorption coefficients (β) of B-doped Si-ncs were found to be 3 times enhanced, compared to those of intrinsic Si-ncs. The response time was faster than 100 fs even at 5 K. The origin of the large nonlinear optical response was discussed, based on the experimental data of n(2), electron spin resonance spectra, and linear absorption spectra.
Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe, 657-8501, Japan. imakita@eedept.kobe‐u.ac.jp
Kenji
K
Imakita
Masahiko
M
Ito
Ryo
R
Naruiwa
Minoru
M
Fujii
Shinji
S
Hayashi