| US 7,532,798 B2 | ||
| Optical waveguide | ||
| David Philip Williams, Bath (United Kingdom); Timothy Adam Birks, Bath (United Kingdom); Philip St. John Russell, Bath (United Kingdom); Peter John Roberts, Bath (United Kingdom); Hendrik Sabert, Stelle (Germany); and Alexander Onischenko, Surrey (United Kingdom) | ||
| Assigned to Crystal Fibre A/S, Birkerod (Denmark) | ||
| Filed on Nov. 02, 2007, as Appl. No. 11/934,231. | ||
| Application 11/934231 is a continuation of application No. 11/155648, filed on Jun. 20, 2005, granted, now 7,321,712. | ||
| Application 11/155648 is a continuation in part of application No. PCT/GB2004/001288, filed on Mar. 22, 2004. | ||
| Application PCT/GB2004/001288 is a continuation in part of application No. PCT/GB2003/005591, filed on Dec. 22, 2003. | ||
| Claims priority of application No. 0229826.3 (GB), filed on Dec. 20, 2002; application No. 0302632.5 (GB), filed on Feb. 05, 2003; application No. 0306593.5 (GB), filed on Mar. 21, 2003; application No. 0306606.5 (GB), filed on Mar. 21, 2003; application No. 0314485.4 (GB), filed on Jun. 20, 2003; application No. 0321991.2 (GB), filed on Sep. 19, 2003; application No. 0322024.1 (GB), filed on Sep. 19, 2003; and application No. 0413843.4 (GB), filed on Jun. 21, 2004. | ||
| Prior Publication US 2008/0138023 A1, Jun. 12, 2008 | ||
| Int. Cl. G02B 6/02 (2006.01); G02B 6/00 (2006.01) | ||
| U.S. Cl. 385—125 [385/122; 385/123; 385/146] | 24 Claims |
| 1. An elongate waveguide for guiding light comprising:
a core comprising an elongate region of relatively low refractive index;
a microstructured region around the core comprising elongate regions of relatively low refractive index interspersed with
elongate regions of relatively high refractive index; and
a boundary at the interface between the core and the microstructured region, the boundary comprising, in the transverse cross-section,
a boundary region of relatively high refractive index, which is connected to the microstructured region at a plurality of
nodes, and at least one relatively enlarged region around the boundary, said enlarged region having a major dimension and
a minor dimension, wherein the length of the major dimension divided by the length of the minor dimension is more than 3.0;
wherein said microstructured region comprises a photonic band-gap structure and wherein said relatively low refractive index
regions make up more than 90% by volume of the photonic bandgap structure.
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