BICHROMOPHORE POLYMERS FOR OPTICAL POWER LIMITING

The highly directional properties of lasers makes them effective weapons when they are directed at the human retina or other sensitive detectors. Lasers are becoming increasingly more reliable, smaller and of lower cost. The recent introduction of practical low-cost tunable lasers circumvents any simple effort to obtain protection by using simple filters. The proposed polymers will contain one or more covalently attached ligands that work cooperatively to transfer charge between them (birchromophore). The net effect is to convent a virtually transparent polymer into a highly absorbing one. An extremely large change in absorption has been demonstrated in solution by chemically reacting similar species with strong oxidants. Our goal I this effort is to prepare a class of polymers containing donor species (strong absorbers) with one or more charge acceptors to facilitate a rapid and reversible absorption change which would protect human eyesight or other sensitive detectors. This approach can utilize different donors and acceptors can utilize can be used to obtain broadband protection. The Workplan involves the synthesis of several polymers followed by their chemical an optical characterization. LPT will make a special effort to develop a structure-function relationship using computational and measurement techniques.