title: Z-scan study of thermal nonlinearities in silicon naphthalocyanine-toluene solution with the excitations of the picosecond pulse train and nanosecond pulse.
abstract: Using the Z-scan technique, we studied the nonlinear absorption and refraction behaviors of a dilute toluene solution of a silicon naphthalocyanine (Si(OSi(n-hexyl)(3))(2), SiNc) at 532 nanometer with both a 2.8-nanosecond pulse and a 21-nanosecond (HW1/eM) pulse train containing 11 18-picosecond pulses 7 nanosecond apart. A thermal acoustic model and its steady-state approximation account for the heat generated by the nonradiative relaxations subsequent to the absorption. We found that when the steady-state approximation satisfactorily explained the results obtained with a 21-nanosecond pulse train, only the thermal-acoustic model fit the 2.8-nanosecond experimental results, which supports the approximation criterion established by Kovsh et al.
authors.forename: Sidney S
authors.initials: SS
authors.lastname: Yang
authors.forename: Tai-Huei
authors.initials: TH
authors.lastname: Wei
authors.forename: Tzer-Hsiang
authors.initials: TH
authors.lastname: Huang
authors.forename: Yun-Ching
authors.initials: YC
authors.lastname: Chang