An Interpenetrating Polymer Network as a Stable Second Order Nonlinear Optical Material: Comparison with the Guest/Host Systems.
Technical rept. 1 Jun 92-31 May 93,
MASSACHUSETTS UNIV LOWELL DEPT OF CHEMISTRY
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Polymeric materials with second order nonlinear optical NLO properties are of much interest for applications such as waveguide electrooptic modulation and frequency doubling devices. These NLO properties are presented when the chromophores are aligned in a noncentrosymmetric manner. The alignment of NLO chromophores in the poled polymers must be sufficiently stable at temperatures above 100 deg C in order to use them in practical devices. Several approaches have been adopted to enhance the temporal stability of the poled polymers. Enhanced temporal stability of second order NLO properties in several poled polymer systems has been achieved by crosslinking reactions. The resulting crosslinked network has a higher glass transition temperature and a denser matrix which prevent the aligned NLO chromophores from relaxing to a random orientation. However, slow decay of second order NLO properties at elevated temperatures was still observed in the polymers. Furthermore, the general form of the relaxation curves for the crosslinking polymers do not appear to be distinctly different from those for the guesthost systems. We have selected an interpenetrating polymer network IPN containing aligned NLO chromophores to test these issues. An IPN is a structure in which two or more networks are physically combined. The IPN is known to be able to remarkably suppress the creep and flow phenomena in polymers. Permanent entanglement of the two polymer chains restrict their mobility which leads to a significantly more stable NLO material. In this paper, we report on the design, synthesis and characterization of an NLO active IPN.... Interpenetrating polymer network, Nonlinear optical polymer.
- *NONLINEAR OPTICS
- *OPTICAL MATERIALS
- TEST AND EVALUATION
- TRANSITION TEMPERATURE
- Polymer Chemistry
- Organic Chemistry
- Electricity and Magnetism