Second- and third-harmonic generation in silicon carbide (SiC) nanopowders embedded in a polymethyl methacrylate (PMMA) film are studied using nano-, pico-, and femtosecond laser pulses. Second- and third-harmonic generation processes are shown to allow the detection of absorptive agglomerates of nanocrystals in transparent materials and the visualization of optical breakdown in nanocomposite materials. Polarization of the third-harmonic signal is shown to be highly sensitive to the polarization of the pump field, permitting third-harmonic generation to be used as a probe for the anisotropy of nanocomposite materials. The second-harmonic signal, on the contrary, has no memory of the initial polarization state of the pump field and is, consequently, ideally suited as a measure of orientation-averaged nonlinearities of nanopowder materials.© 2004 by ASTRO, Ltd.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)
Konorov, S. O., Ivanov, A. A., Alfimov, M. V., Sidorov-Biryukov, D. A., Podshivalov, A. A., Petrov, A. N., ... Zheltikov, A. M. (2004). Generation of the second and third harmonics of femtosecond Cr: Forsterite laser pulses in SiC/PMMA nanopowder films. Laser Physics Letters, 1(1), 37 - 41. https://doi.org/10.1002/lapl.200310009