Self-diffraction at a dynamic photonic crystal formed in a colloidal solution of quantum dots

• Published in: JETP letters 2016-11, Vol.104 (10), p.674-678
• Main Authors: Smirnov, A. M., Golinskaya, A. D., Ezhova, K. V., Mantsevich, V. N., Dneprovskii, V. S.
• Format: Article
• Language: English
• Subjects: Absorption; Atomic; Biological and Medical Physics; Biophysics; Colloids; Electron beams; Gaussian beams (optics); Gratings (spectra); Laser beams; Molecular; Normal distribution; Optical and Plasma Physics; Optics and Laser Physics; Particle and Nuclear Physics; Photon beams; Photonic crystals; Physics; Physics and Astronomy; Quantum dots; Quantum Information Technology; Refractivity; Solid State Physics; Spintronics
• ISSN: 0021-3640; 1090-6487
• DOI: 10.1134/S0021364016220136

Self-diffraction at a one-dimensional dynamic photonic crystal formed in the colloidal solution of CdSe/ZnS quantum dots has been discovered. This self-diffraction appears simultaneously with self-diffraction at induced transparency channels at the resonant excitation of the main electron–hole (excitonic) transition of quantum dots by two laser beams with a Gaussian intensity distribution over the cross section. It is shown that a nonlinear change in the absorption of colloidal quantum dots results in the formation of a transparency channel and an induced amplitude diffraction grating, and a significant nonlinear change in the refractive index (Δ n ≈ 10 −3 ) in the absorbing medium is responsible for the formation of the dynamic photonic crystal. Self-diffracted laser beams are revealed propagating not only in directions corresponding to self-diffraction at the induced diffraction grating but also in directions satisfying the Laue condition.