Patent ID: 7526165
Filing Date: 2009-04-28
Classification: G02B,H01S

Abstract:
1. An optical fibre having a longitudinal, optical axis, and a cross section perpendicular to the longitudinal axis, the optical fibre being adapted to guide light at an operating wavelength λ, the optical fibre comprising: a. a first core region disposed around the longitudinal, optical axis, the first core region exhibiting a predetermined refractive index profile n b. a second core region surrounding the first core region, the second core region exhibiting a predetermined refractive index profile n c. a cladding region surrounding the second core region and comprising a multitude of longitudinally extending spaced apart micro-structural holes disposed in a cladding material, the cladding material having a refractive index n d. a first fibre cross section having a first cross sectional area; e. a second fibre cross section having a second cross sectional area which is smaller than the first cross sectional area; f. the first and second fibre cross sections being separated by a tapered length of the optical fibre over which the cross-sectional physical dimensions of the fibre, including the micro-structural holes, are tapered down from the first to the second cross section; and wherein in the first and second cross sectional areas, the refractive index profiles n