Generation of the second and third harmonics of femtosecond Cr: forsterite laser pulses in SiC/PMMA nanopowder films

✍ Scribed by S.O. Konorov; A.A. Ivanov; M.V. Alfimov; D.A. Sidorov-Biryukov; A.A. Podshivalov; A.N. Petrov; L. Fornarini; M. Carpanese; M. Avella; M.E. Errico; R. Fantoni; A.M. Zheltikov

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 371 KB
• Volume: 1
• Category: Article
• ISSN: 1612-2011
• DOI: 10.1002/lapl.200310009

✦ Synopsis

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.