ULTRAFAST BROAD-BAND PASSIVE LASER SHIELDS BASED ON NOVEL SEMICONDUCTOR/CONDUCTING POLYMER INTERFACE TECHNOLOGY

A NOVEL TECHNOLOGY FOR FABRICATION OF BROAD-BAND, DYNAMIC (SWITCHABLE), PASSIVE, ULTRAFAST (SUBNANOSECOND RISE AND FALL TIMES) LASER SHIELDS IS PROPOSED, BASED ON INTERFACING SEMICONDUCTOR (SC) ELECTRODES TO CONDUCTING POLYMERS (CPS). THE CP NORMALLY SWITCHED FROM A TRANSPARENT TO AN OPAQUE STATE ELECTROCHEMICALLY, IS SWITCHED BY THE SC ON LASER PHOTOACTIVATION, WHICH PROVIDES BOTH THE TRIGGER AND THE EMF FOR SWITCHING. THE SWITCHING RATE-LIMITING PROCESS IS CHARGE TRANSFER ACROSS THE SC/CP INTERFACE, WITH AN RC TIME CONSTANT BASED ON ACTUAL MEASUREMENTS OF 100 PSEC - 1 NSEC, AND CHARGE CONDUCTION WITHIN THE POLYMER, ALSO VERY RAPID. PRELIMINARY DATA (RESULTS PRESENTED HEREIN) SHOW EMINENTLY THE FEASIBILITY OF THE METHOD. A MULTIDISCIPLINARY APPROACH IS PROPOSED WITH MAJOR EXPERIMENTS AT THE STATE-OF-THE-ART PICOSECOND LASER FACILITIES OF THE REGIONAL LASER AND BIOTECHNOLOGY LABORATORIES (RLBL), U. OF PA., PHILADELPHA, WITH WHICH GUMBS HAS AN ONGOING RELATIONSHIP. EXTENSIVE OTHER CONTRACTUAL WORK AT GUMBS IN LASER SHIELDS STRENGTHENS THE PROPOSAL. SWITCHING AT INTENSITIES JUST ABOVE THE MAXIMUM PERMISSIBLE EXPOSURES (MPES) IS SHOWN TO OCCUR.