Nonlinear Absorptions of CdSeTe Quantum Dots under Ultrafast Laser Radiation

Abstract EN

The oil-soluble alloyed CdSeTe quantum dots (QDs) are prepared by the electrostatic method.

The basic properties of synthesized CdSeTe QDs are characterized by UV-Vis absorption spectroscopy, photoluminescence spectroscopy, inductively coupled plasma mass spectrometry, and transmission electron microscope.

The off-resonant nonlinear optical properties of CdSeTe QDs are studied by femtosecond Z-scan at 1 kHz (low-repetition rate) and 84 MHz (high-repetition rate).

Nonlinear absorption coefficients are calculated under different femtosecond laser excitations.

Due to the long luminescent lifetime of CdSeTe QDs, under the conditions of high-repetition rate, for open-aperture curve, heat accumulation and bleaching of ground state are responsible for the decrease of two-photon absorption (TPA) coefficient.