On percolation and circular Bragg phenomenon in metallic, helicoidally periodic, sculptured thin films

✍ Scribed by Akhlesh Lakhtakia

• Book ID: 102656053
• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 945 KB
• Volume: 24
• Category: Article
• ISSN: 0895-2477
• DOI: 10.1002/(sici)1098-2760(20000220)24:4<239::aid-mop10>3.0.co;2-#

✦ Synopsis

The concept of local homogenization is in¨oked in the ¨isible and sub¨isible frequency regimes to estimate the permitti¨ity ( ) dyadics of thin-film helicoidal bianisotropic media TFHBM ᎏa canonical class of sculptured thin films with a helicoidally periodic microstruc-tureᎏmade of a metal. Examination of the components of the permit-ti¨ity dyadics, as well as of the co-and cross-polarized reflectances of axially excited, metallic TFHBM half spaces, re¨eals that three different absorbing-dielectric-to-metal transitions will occur as the metallic ¨olumetric fraction is increased, but only two will be optically sensed using normally incident plane wa¨es. The first transition is shown to ¨irtually eliminate the circular Bragg phenomenon characteristically displayed by axially excited, dielectric TFHBM.