Patent number: 6735369

Hollow optical fiber and method for manufacturing the same

Original Assignee: Machida Endoscope Co., Ltd.

Field of technology: Optics

Patent granted on: Tue, 11 May 2004

Patent drawing

Abstract

A hollow optical fiber 10 has an intermed ate dielectric layer 12 interposed between an inner periphery side dielectric layer 11 facing a hollow core portion 10a and a metal layer 13. The inner periphery side dielectric layer 11 is formed of calcium fluoride. The intermediate dielectric layer 12 is formed of yttrium fluoride. Metal of the metal layer 13 can be prevented from dispersing into the dielectric layers 12, 11 by the intermediate dielectric layer 12 formed of yttrium fluoride. The hollow optical fiber 10 is manufactured by vapor depositing calcium fluoride on an outer peripheral surface of an acid-soluble glass tube 20 (base material), then vapor depositing yttrium fluoride on its outer peripheral surface, then vapor depositing a metal layer formed of silver, gold or the like on its outer peripheral surface, and thereafter, dissolving the glass tube 20 with acid.