A light-diffusing optical element with efficient coupling to light sources with high numerical aperture. The light-diffusing optical element includes a higher index core surrounded by a lower index cladding. The cladding includes scattering centers that scatter evanescent light entering the cladding from the core. The scattered light exits the element to provide broad-area illumination along the element. Scattering centers include dopants, nanoparticles and/or internal voids. The core may also include scattering centers. The core is glass and the cladding may be glass or a polymer. The element features high numerical aperture and high scattering efficiency.

The invention relates to an optical fiber 1 comprising a core 2 and a cladding 3 surrounding the core 2 and having an outer diameter of 125 m, the optical fiber 1 comprising a cured primary coating 4 directly surrounding the cladding 3 and a cured secondary coating 5 directly surrounding the cured primary coating 4, said cured primary coating 4 having a thickness t.sub.1 between 10 and 18 m and an in-situ tensile modulus Emod.sub.1 between 0.10 and 0.18 MPa, said cured secondary coating 5 having a thickness t.sub.2 lower or equal to 18 m and an in-situ tensile modulus Emod.sub.2 between 700 and 1200 MPa, wherein said first and second thicknesses and said first and second in-situ tensile moduli satisfy the following equation: 4%<(t.sub.1t.sub.2Emod.sub.1Emod.sub.2.sup.3)/(t.sub.1.sub._.sub.normt.sub.2.sub._.sub.normEmod.sub.1.sub._.sub.normEmod.sub.2.sub._.sub.norm.sup.3)<50%

The present invention, as disclosed and described herein, in one aspect thereof comprises a preform for making a vortex optical fiber includes a glass cylinder formed substantially of silicone dioxide that defines a core portion along a longitudinal axis of the glass cylinder and a cladding portion surrounding the core portion. The glass cylinder further defines a plurality of holes running parallel to the longitudinal axis from a first end of the glass cylinder to a second end of the glass cylinder.

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 laser delivery device may include a connector portion at a proximal end of the laser delivery device and an optical fiber connecting the connector portion to a distal end of the laser delivery device. The connector portion may include a capillary at least partially surrounding a proximal portion of the optical fiber, and the capillary may include dimples on at least a portion of a circumferential surface thereof.

A preform for making a vortex optical fiber comprises a glass cylinder formed substantially of silicone dioxide that defines a core portion along a longitudinal axis of the glass cylinder and a cladding portion surrounding the core portion. The glass cylinder further defines a plurality of holes running parallel to the longitudinal axis from a first end of the glass cylinder to a second end of the glass cylinder.

An optical fiber includes a core, a depressed inner cladding surrounding the core, and an outer cladding surrounding the inner cladding, where a refractive index profile of the core includes an power distribution in which an index is 3.5 or more and 6 or less, a relative refractive index difference .sup. of the inner cladding with respect to the adding is set such that an absolute value |.sup.| thereof is 0.01% or more and 0.045% or less, a radius r1 of the core and an outer circumference radius r2 of the inner cladding are set such that a ratio r1/r2 thereof is 0.2 or more and 0.6 or less, a cable cutoff wavelength .sub.cc of 22 m is 1260 nm or less, and a mode field diameter MFD at a wavelength of 1310 nm is 8.6 m or more and 9.5 m or less.

Holey fibers provide optical propagation. In various embodiments, a large core holey fiber comprises a cladding region formed by large holes arranged in few layers. The number of layers or rows of holes about the large core can be used to coarse tune the leakage losses of the fundamental and higher modes of a signal, thereby allowing the non-fundamental modes to be substantially eliminated by leakage over a given length of fiber. Fine tuning of leakage losses can be performed by adjusting the hole dimension and/or spacing to yield a desired operation with a desired leakage loss of the fundamental mode. Resulting holey fibers have a large hole dimension and spacing, and thus a large core, when compared to traditional fibers and conventional fibers that propagate a single mode. Other loss mechanisms, such as bend loss and modal spacing can be utilized for selected modes of operation of holey fibers.

Disclosed herein is an optical cable comprising a plurality of cable sensors helically wound around a support; and an outer jacket that is disposed on the plurality of cable sensors and surrounds the plurality of cable sensors; where each cable sensor comprises an optical fiber; where the optical fiber comprises an optical core upon which is disposed a cladding; a primary coating; a deformable material surrounding the optical fiber; and an outer tube surrounding the deformable material; where the optical fiber is of equal length to the outer tube; and where an allowable strain on the optical cable with zero stress on the optical fiber is determined by equations (1) and (2) below:

[00001]$\begin{array}{cc}\mathrm{.Math.}=\frac{\sqrt{{{}^2\left(D+\frac{d}{2}\right)}^2+p^2}}{p}-\frac{\sqrt{{{}^2\left(D-\frac{d}{2}\right)}^2+p^2}}{p}=\frac{{}^2.Math.\mathrm{dD}}{p^2}=\frac{10.Math..Math.\mathrm{dD}}{p^2}& \left(1\right)\\ \mathrm{.Math.}100=\mathrm{Percent}.Math..Math.\mathrm{elongation}.Math..Math.\mathrm{or}.Math..Math.\mathrm{contraction};& \left(2\right)\end{array}$

where d is the amount of optical fiber clearance for free movement within the loose tube, D is an average pitch diameter of the plurality of cable sensors and p is an average pitch length of a helical turn of the plurality of c

A laser delivery device may include a connector portion at a proximal end of the laser delivery device and an optical fiber connecting the connector portion to a distal end of the laser delivery device. The connector portion may include a capillary at least partially surrounding a proximal portion of the optical fiber, and the capillary may include dimples on at least a portion of a circumferential surface thereof.