A microstructured optical fiber for generating supercontinuum light. The optical fiber includes a core and a cladding region surrounding the core. The optical fiber includes a first fiber length section, a second fiber length section as well as an intermediate fiber length section between said first and second fiber length sections. The first fiber length section has a core with a first characteristic core diameter larger than about 7 ?m. The second fiber length section has a core with a second characteristic core diameter, smaller than said first characteristic core diameter. The intermediate length section of the optical fiber includes a core which is tapered from said first characteristic core diameter to the second characteristic core diameter over a tapered length. Also, a supercontinuum light source including an optical fiber and a pump light source.

The invention relates to a supercontinuum light source comprising a microstructured optical fiber and a pump light source. The microstructured optical fiber comprises a core and a cladding region surrounding the core, as well as a first fiber length section, a second fiber length section and an intermediate fiber length section between said first and second fiber length sections. The first fiber length section comprises a core with a first characteristic core diameter. The second fiber length section comprises a core with a second characteristic core diameter, smaller than said first characteristic core diameter, where said second characteristic core diameter is substantially constant along said second fiber length section. The intermediate length section of the optical fiber comprises a core which is tapered from said first characteristic core diameter to said second characteristic core diameter over a tapered length.

An optical fiber design method according to the present invention is a design method of a photonic crystal fiber having a plurality of holes arranged in the optical fiber along a longitudinal direction, in which a required effective cross-sectional area is calculated from a light wavelength, a transmission distance, and output power such that, in a cross section, a hole ratio which is an area of the holes per unit area is larger in a central side than in an outer side in a portion corresponding to a cladding, and a fiber structure (hole diameter and hole interval) corresponding to the effective cross-sectional area is calculated.

A photonic crystal fiber according to the present invention has a plurality of holes arranged in the optical fiber along a longitudinal direction, in which the holes are arranged such that, in a cross section, a hole ratio which is an area of the holes per unit area is larger in a central side than in an outer side in a portion corresponding to a cladding and that a wide core area can be obtained while the number of modes that can be propagated is limited to several. Moreover, in a high-power optical transmission system according to the present invention, the amount of axis misalignment between the central axis of a laser oscillator and the central axis of the photonic crystal fiber is less than or equal to a certain amount.

A method for manufacturing a capillary usable as part of a hollow-core photonic crystal fiber. The method includes obtaining a capillary having capillary wall including a first wall thickness; and chemically etching the capillary wall to reduce the wall thickness of the capillary wall. During performance of the etching, a control parameter is locally varied along the length of the capillary, the control parameter relating to reactivity of an etchant used in the etching, so as to control the etched wall thickness of the capillary wall along the capillary length. Also disclosed is a capillary manufactured by such a method and various devices including such a capillary.

The invention relates to a microstructured optical fiber for generating supercontinuum light upon feeding of pump light. The light can be incoherent light. The microstructured optical fiber has a first section and a second section, where the first and second sections have one or more different features. The invention also relates to a supercontinuum source comprising a microstructured optical fiber according to the invention.

The invention relates to a supercontinuum light source comprising a microstructured optical fiber and a pump light source. The microstructured optical fiber comprises a core and a cladding region surrounding the core, as well as a first fiber length section, a second fiber length section and an intermediate fiber length section between said first and second fiber length sections. The first fiber length section comprises a core with a first characteristic core diameter. The second fiber length section comprises a core with a second characteristic core diameter, smaller than said first characteristic core diameter, where said second characteristic core diameter is substantially constant along said second fiber length section. The intermediate length section of the optical fiber comprises a core which is tapered from said first characteristic core diameter to said second characteristic core diameter over a tapered length.

An optical connector comprises a first optical waveguide including a plurality of cores each extending along a first direction, the first optical waveguide having a first end face, wherein the cores are arranged on the first end face at positions except a position of a central axis of the first optical waveguide, and a first lens having a second end face and a third end face in the first direction, the first lens having an optical axis extending along the first direction. The first optical waveguide and the first lens are arranged so that the central axis of the first optical waveguide coincides with the optical axis of the first lens. The second end face is positioned facing the first end face, and the third end face extends along a plane perpendicular to an optical axis of the first optical waveguide.

The invention relates to a microstructured optical fiber for generating supercontinuum light. The optical fiber comprises a core and a cladding region surrounding the core. The optical fiber comprises a first fiber length section, a second fiber length section as well as an intermediate fiber length section between said first and second fiber length sections. The first fiber length section has a core with a first characteristic core diameter larger than about 7 m. The second fiber length section has a core with a second characteristic core diameter, smaller than said first characteristic core diameter. The intermediate length section of the optical fiber comprises a core which is tapered from said first characteristic core diameter to said second characteristic core diameter over a tapered length. The invention also relates to a supercontinuum light source comprising an optical fiber according to the invention and a pump light source.

The invention relates to a supercontinuum light source comprising a microstructured optical fiber and a pump light source. The microstructured optical fiber comprises a core and a cladding region surrounding the core, as well as a first fiber length section, a second fiber length section and an intermediate fiber length section between said first and second fiber length sections. The first fiber length section comprises a core with a first characteristic core diameter. The second fiber length section comprises a core with a second characteristic core diameter, smaller than said first characteristic core diameter, where said second characteristic core diameter is substantially constant along said second fiber length section. The intermediate length section of the optical fiber comprises a core which is tapered from said first characteristic core diameter to said second characteristic core diameter over a tapered length.