A method of making a microstructured optical fiber comprising loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T.sub.anneal; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material.

A supercontinuum light source includes a microstructured optical fiber, and a feeding unit arranged for feeding pump pulses to the microstructured optical fiber, wherein the feeding unit comprises a picosecond laser and one or more amplifiers, wherein the microstructured optical fiber is a silica fiber wherein at least a part of the core being of silica or doped silica, and including a core including core material and a cladding surrounding the core, and at least the core material is loaded with deuterium to have an OD absorption peak around 1870 nm, wherein the feeding unit is spliced to the microstructured optical fiber.

Provided is a light diffusion device capable of uniformly emitting light from the outer circumferential surface of a light-emitting part of an optical fiber. This light diffusion device 1 comprises an optical fiber 20 composed of a core 21 positioned on the radial center side and a clad 22 positioned on the outer circumferential side of the core 21, and emits laser light, which is incident from a proximal end section of the optical fiber 20, from the distal end side of the optical fiber 20, wherein: the optical fiber 20 has a light transmission part 20a which transmits the laser light incident from the proximal end section toward the distal end section, and a light-emitting part 20b which emits, from the outer circumferential surface, the laser light transmitted from the light transmission part 20a by removing a portion positioned on the outer circumferential side of the clad 22 on the distal end side; and the maximum thickness of the clad 22 in the light-emitting part 20b is smaller than the thickness of the clad 22 in the light transmission part 20a.

A supercontinuum light source includes a microstructured optical fiber, and a feeding unit arranged for feeding pump pulses to the microstructured optical fiber, wherein the feeding unit comprises a picosecond laser and one or more amplifiers, wherein the microstructured optical fiber is a silica fiber wherein at least a part of the core being of silica or doped silica, and including a core including core material and a cladding surrounding the core, and at least the core material is loaded with deuterium to have an OD absorption peak around 1870 nm, wherein the feeding unit is spliced to the microstructured optical fiber.

An all-fiber isolator as an optical isolator comprises: an optical fiber acting as an optical light guide for propagating incident light; and a Faraday rotator for rotating by 45 a plane of polarization polarized by the polarizer. The all-fiber isolator exhibits a magneto-optic effect enough to be used as an optical isolator at a visible light wavelength by including quantum dots in a core layer and/or an internal cladding layer of the optical fiber.

A method of making a microstructured optical fiber including loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T.sub.anneal; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material.

A method of making a microstructured optical fiber including loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T.sub.anneal; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material.

A polarization-maintaining dispersion-compensation microstructure fiber includes an inner core, an air-hole array in area 1 and an air-hole array in area 2. The air holes in the area 1 and 2 air-hole arrays are arranged in square lattice. The air-hole arrays in areas 1 and 2 are dislocated by half-layer along y-direction. In area 1, 2 air holes in the middle row are omitted to form a solid area as the inner core. 2 outer cores are located in 2 sub-areas of area 2, and each outer core contains 2 air holes. The long (or short) axes of the inner and outer cores are perpendicular, and the center points of the inner core and the two outer cores are located on the x-axis.

The present invention provides an optical fiber (100) (i.e., a few-mode optical fiber (100) comprising: at least three consecutive up-doped regions (i.e., core region) (102); and a cladding region (104) surrounding the at least three consecutive up-doped regions (102). In particular, the at least three consecutive regions (102) comprising a first up-doped region (106) having a first maximum refractive index (n1max), a second up-doped region (108) having a second maximum refractive index (n2max), and a third up-doped region (110) having a third maximum refractive index (n3max) where n2max>n3max>n1max. Further, the optical fiber (100) is constructed to allow only LP.sub.01 mode of optical light and LP.sub.11 mode of optical light to propagate through the few-mode optical fiber (100) and possesses high effective area and low Differential Mode Delay.