Optical properties of azo (EO) chromophore (DR1) doped in poly amic acid (PAM)
In this work, we studied the effects of annealing on the structural and optical properties of an azo electro optic (EO) polymer, Disperse Red1 (DR1), doped in Poly Amic Acid (PAM). Thin films were deposited on glass substrates by spin coating technique. The films were annealed at 195°C. The Structural and optical properties of the doped films were investigated by using UV-VIS spectra, Atomic Force Microscopy (AFM) and Prism Coupling technique. The number of modes, angles of coupling, thickness and refractive index were compared before and after annealing. The experimental results, showed 24nm blue shift in the photon absorption peak and number of modes and surface roughness of thin films decreased after annealing. Thickness was reduced about 1um and refractive index was increased by 0.03.
Thermal stability of electro‐optic response in poled polyimide systems
Using polyimide as host in a guest‐host thin film we demonstrate the first poled‐polymer electro‐optic response stable at temperatures up to 150 °C (samples poled and cured at 250 °C). A coplanar‐electrode poling geometry is used so that the molecular alignment of the guest dye between the electrodes is coincident with the free volume of the host. We hypothesize that ‘‘high’’ temperature poling during the imidization process, when the polyimide forms rings and densifies, accounts for the excellent poled response stability.
Shakespeare, Machiavelli, and Montaigne: Power and Subjectivity from Richard II to Hamlet
HISTORICISM AND THE CULTURAL PRESENT IN SHAKESPEARE STUDIES: SUBJECTIVITY IN EARLY AND LATE MODERNITY HAMLET AND THE TRAGEDY OF THE SUBJECT