ABSTRACT
In the present study, a series of holographic gratings were recorded in a single location of nickel-ion-doped photopolymer film using different methods of multiplexing. The uniformity of their diffraction efficiency was shown to improve by using an exposure time scheduling method for holographic recording. Thirty-five gratings were recorded in the 130 µm thick photopolymer material with M#=6.18 and an average diffraction efficiency of 3.24% using peristrophic multiplexing. In the next step, a combination of peristrophic and angular multiplexing was used for storing 50 gratings in the material with a dynamic range of 7 and a mean diffraction efficiency of 2.15%.
ABSTRACT
The ground state and excited state dipole moment of a series of alkyl substituted para-nitroaniline derivatives is reported. Ground state dipole moment was determined by the Debye-Guggenheim method and the excited state dipole moment was estimated using the solvatochromic method. For all molecules under investigation, the excited state dipole moment was found to be higher than the ground state dipole moment. The molecules exhibited positive solvatochromism.