The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 03, 2005
Filed:
Apr. 06, 2001
Jeremy J. Baumberg, Winchester, GB;
Martin D. B. Charlton, Southampton, GB;
Maria C. Netti, Southampton, GB;
Gregory J. Parker, Brockenhurst Hants, GB;
Majd E. Zoorob, Southampton, GB;
Jeremy J. Baumberg, Winchester, GB;
Martin D. B. Charlton, Southampton, GB;
Maria C. Netti, Southampton, GB;
Gregory J. Parker, Brockenhurst Hants, GB;
Majd E. Zoorob, Southampton, GB;
BTG International Limited, London, GB;
Abstract
In order to create an optical device with a photonic band gap extending in two dimensions and with very uniform properties in any direction and for any polarisation state, to within 1%, air holes are etched within a substrate of low refractive index material such silicon oxynitride or silica glass. The ratio of air hole area to the remainder of the substrate is low, being less than 35%. The air holes define a quasicrystal structure, having twelve fold symmetry, being based on a square-triangle system. In another development, an etched substrate with a regular crystal structure or quasicrystal structure exhibits a non-linear refractive index. Two adjacent areas in such a substrate have different lattice properties, or have defects in the lattices, to create a unidirectional transmission path (diode action). A further beam of light may be used to modulate the transmission path by reason of the non-linear refractive index.