Skip to content
University of Maryland LibrariesDigital Repository at the University of Maryland
    • Login
    View Item 
    •   DRUM
    • Theses and Dissertations from UMD
    • UMD Theses and Dissertations
    • View Item
    •   DRUM
    • Theses and Dissertations from UMD
    • UMD Theses and Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Characterization of Linear Electro-Optic Effect of Poled Organic Thin Films

    Thumbnail
    View/Open
    umi-umd-5189.pdf (2.175Mb)
    No. of downloads: 2807

    Date
    2008-02-29
    Author
    Park, Dong Hun
    Advisor
    Lee, Chi H
    Herman, Warren N
    Metadata
    Show full item record
    Abstract
    The goal of this thesis is to re-evaluate both Teng-Man and attenuated total reflection (ATR) methods for measuring the linear electro-optic (EO) coefficients of poled organic thin films based on a multilayer structure containing a transparent conducting oxide (TCO) layer. The linear EO properties are often characterized using the Teng-Man reflection method. However, it has been reported that experimental error can result from ignoring multiple reflections and that an accurate determination of the EO effect could be achieved only by a numerical calculation that applies anisotropic Fresnel equations to the multilayer structure. We present new closed-form expressions for analysis of Teng-Man measurements of the EO coefficients of poled polymer thin films. These expressions account for multiple reflection effects using a rigorous analysis of the multilayered structure for varying angles of incidence. The analysis based on plane waves is applicable to both transparent and absorptive films and takes into account the properties of the TCO electrode layer and buffer layers. Methods for fitting data are presented and the error introduced by ignoring the TCO layer and multiple reflections is discussed. We also discuss the effect of Gaussian beam optics and the suitability of a thick z-cut LiNbO3 crystal as a reference to validate the Teng-Man measurement. Simply taking the metal electrode off the Teng-Man sample makes it feasible to use the ATR method using a metal-coated prism. This technique has the capability of measuring anisotropic indices of refraction along with film thicknesses. In addition, it enables measurement of r13 and r33 separately without an assumption for the ratio of r13 to r33 as required in the Teng-Man method. We have found that the ATR analysis based on a three-layer waveguide structure (air/film/substrate) can produce a large error especially when the film supports a single guided mode and the ATR analysis based on a multilayer structure containing a TCO layer gives you a more reliable estimation. We discuss the error introduced by using the three-layer waveguide structure and compare to using the multilayer structure. Finally, we discuss the characterization of the optical property of TCO's using ellipsometeric analysis, which is required for both the rigorous Teng-Man and ATR analysis. Representative experimental results showing that the result from the ATR method based on the multilayer structure shows a good agreement with that from the rigorous Teng-Man analysis are presented. We have measured a very high linear electro-optic coefficient (r33=350 pm/V) from a NLO film (AJ-TTE-II, synthesized by Alex Jen's group at University of Washington) at 1310 nm wavelength, which is ~12 times higher than the best inorganic electro-optic crystal LiNbO3.
    URI
    http://hdl.handle.net/1903/7861
    Collections
    • Electrical & Computer Engineering Theses and Dissertations
    • UMD Theses and Dissertations

    DRUM is brought to you by the University of Maryland Libraries
    University of Maryland, College Park, MD 20742-7011 (301)314-1328.
    Please send us your comments.
    Web Accessibility
     

     

    Browse

    All of DRUMCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    LoginRegister
    Pages
    About DRUMAbout Download Statistics

    DRUM is brought to you by the University of Maryland Libraries
    University of Maryland, College Park, MD 20742-7011 (301)314-1328.
    Please send us your comments.
    Web Accessibility