Generation of the third harmonic in fullerene-containing polyimide films by picosecond radiation of the Nd : YAG laser

The results of the studies on the transformation of the frequency of laser radiation in polyimide films doped by C-70 are presented. The nonlinear sus ceptibility (chi ((3))) of polyimide 6B films with various concentrations o f C-70 is studied by third-harmonic generation. At a wavelength of 1064 nm, the value of chi ((3))(-3 omega; omega, omega, omega) is 9 x 10(-13) esu. The effect of the nonlinear variation in the refractive index of the fuller ene-containing films on the phase matching between the pumping and third-ha rmonic waves is ana zed. The third harmonic of the Nd : YAG laser radiation was generated with the efficiencies 6 x 10(-6) and 10(-6) in the films wit h the C-70 concentration of 0.5 and 0.2%, respectively. (C) 2001 MAIK "Nauk a/Interperiodica".