OPTICAL NONLINEARITY OF CdSe AND CdSe-C-60 QUANTUM DOT

摘要

The third-order optical nonlinear properties of CdSe quantum dots (QDs) and CdSe-C-60 QDs are investigated by Z-scan technique with picosecond pulses at the wavelength of 800 nm. The value of the nonlinear absorption coefficient beta of CdSe-C-60 QDs is measured to be 2.9 cm/GW, which is about two times larger than that of CdSe QDs. The nonlinear refraction index gamma of CdSe-C-60 QDs is -2.8 x 10(-3) cm(2)/GW, which is about seven times larger than that of CdSe QDs. Presence of C-60 contributes to the larger optical nonlinearity of CdSe-C-60 QDs comparing with CdSe QDs.