1 May 2014 Self-action effects in semiconductor quantum dots
Author Affiliations +
Two-dimensional (2D) dynamic photonic crystal regime has been utilized to investigate self-diffraction effect and nonlinear optical properties of excitons in CdSe/ZnS colloidal quantum dots (QDs). Self-diffraction at 2D photonic crystal arises for three intersecting beams of Nd+3:YAG laser second harmonic in the case of one-photon resonant excitation of the exciton (electron - hole) transition QDs. The relaxation time of excited excitons has been measured by pump and probe technique at induced one-dimensional transient diffraction grating. Two-exponential decay with initial fast and slow parts was discovered. Self-action effect has been discovered in the case of stationary resonant excitation of excitons in CdSe/ZnS QDs by the beam of second harmonic of powerful 12-nanosecond laser pulses. The bleaching of exciton absorption and the creation of transparency channel (this effect provokes self-diffraction of the second harmonic beam) was explained by the dominating coexisting and competing processes of state filling in stationary excited quantum dots and Stark-shift of exciton spectral band. The peculiarities of the influence of these processes at the change of exciton absorption in quantum dots in the case of different detuning from exciton resonance (quantum dots with different size have been used) was analyzed.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
V. S. Dneprovskii, V. S. Dneprovskii, A. R. Kanev, A. R. Kanev, M. V. Kozlova, M. V. Kozlova, A. M. Smirnov, A. M. Smirnov, "Self-action effects in semiconductor quantum dots", Proc. SPIE 9136, Nonlinear Optics and Its Applications VIII; and Quantum Optics III, 91361Y (1 May 2014); doi: 10.1117/12.2052459; https://doi.org/10.1117/12.2052459

Back to Top