Scholarly Works, Materials Science and Engineering (MSE)

Permanent URI for this collection

https://hdl.handle.net/10919/24370
Research articles, presentations, and other scholarship

Browse

Browsing Scholarly Works, Materials Science and Engineering (MSE) by Subject "2nd-harmonic generation"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Enhanced Absorption And Electro-Optic Pockels Effect Of Electrostatically Self-Assembled Cdse Quantum Dots
    Zhang, F. J.; Zhang, L. M.; Wang, Y. X.; Claus, Richard O. (Optical Society of America, 2005-10-01)
    The spectrum and electro-optic properties of CdSe quantum dots are studied. Spectrum wavelength shifts that are due to the quantum size effect and to the electro-optic Stark effect are investigated. It is found that CdSe quantum dot-polymer composites formed by an electrostatic self-assembly (ESA) technique exhibit high internal electric fields. Using the second-order perturbation theory of the ls-ls energy shift (Stark effect), we estimate the internal field of the ESA film to be as high as 2.6 X 10(8) V/m. This value results in a much higher absorption coefficient and electro-optic coefficients for ESA films than for their bulk crystal counterparts or for spin-coated film samples. The relationships among unusual spectra, film structure, and high electro-optic response are analyzed. These results are useful both for understanding the physical mechanisms of semiconductor quantum dots and for developing high-performance photonic devices. (c) 2005 Optical Society of America.
  • Thumbnail Image
    Two-phonon coupling to the antiferromagnetic phase transition in multiferroic BiFeO(3)
    Ramirez, Mariola O.; Krishnamurthi, M.; Denev, S.; Kumar, Amit; Yang, Seung-Yeul; Chu, Ying-Hao; Saiz, Eduardo; Seidel, Jan; Pyatakov, Alexander P.; Bush, A.; Viehland, Dwight D.; Orenstein, J.; Ramesh, R.; Gopalan, Venkatraman (AIP Publishing, 2008-01-01)
    A prominent band centered at similar to 1000-1300 cm(-1) and associated with resonant enhancement of two-phonon Raman scattering is reported in multiferroic BiFeO(3) thin films and single crystals. A strong anomaly in this band occurs at the antiferromagnetic Neel temperature, T(N)similar to 375 degrees C. This band is composed of three peaks, assigned to 2A(4), 2E(8), and 2E(9) Raman modes. While all three peaks were found to be sensitive to the antiferromagnetic phase transition, the 2E(8) mode, in particular, nearly disappears at T(N) on heating, indicating a strong spin-two-phonon coupling in BiFeO(3). (c) 2008 American Institute of Physics.