Dichroic ultraviolet light filters.
With the intention to produce dichroic filters for use in photoluminescent systems that rely on polarized UV light, we synthesized a number of linear, dichroic dyes, which absorb mainly in the near-UV range of the electromagnetic spectrum. These dyes were designed for compatibility with common thermoplastic polymers such as linear low-density poly(ethylene), poly(ethylene terephthalate), and polyamide-12. Films of these host polymers that consisted of 0.2% by weight of various dichroic UV dyes were produced by common melt-processing schemes. Uniaxial drawing of these films yielded highly dichroic UV filters with dichroic ratios in absorption that in some cases exceeded 100. The fact that these free-standing films display little or no coloration and are environmentally stable makes them useful for various applications that involve generation of polarized UV light.
Kocher
Christoph
C
Department of Materials, Eidgenössische Technische Hochschule Zürich, Universitätsstrasse 41, UNO C14, CH-8092 Zürich, Switzerland. ckocher@mat.ethz.ch
Weder
Christoph
C
Smith
Paul
P