An illumination module includes a light source and a light diffusion fiber coupled to the light source. The light diffusion fiber defines a plurality of indent cuts at an outer sidewall thereof. An arrangement density of the indent cuts gradually decreases along a direction away from the light source.

Tapered core fibers are produced using tapered core rods that can be etched or ground so that a fiber cladding has a constant diameter. The tapered core can be an actively doped core, or a passive core. One or more sleeving tubes can be collapsed onto a tapered core rod and exterior portions of the collapsed sleeving tubes can be ground to provide a constant cladding diameter in a fiber drawn from the preform.

A non-radial array of microstructure elements provides enhanced wavelength selective filtering. The elements are arranged along a line that does not intersect the center of the core. In this configuration, the first coupling element in an array that is nearest to the core is a non-integer array unit spacing from the main waveguide where the array unit spacing is defined as the flat to flat distance of a hexagonal cell.

In some implementations, an emitter module may include an emitter array that includes multiple emitters, and an optical fiber that includes multiple cores within a single cladding. The emitter array may be optically coupled to a tip of the optical fiber such that each emitter, of the multiple emitters of the emitter array, is optically coupled to a respective core of the multiple cores of the optical fiber. The optical fiber may include an integral lens at the tip of the optical fiber. The integral lens at the tip of the optical fiber may be in alignment with the multiple cores of the optical fiber.

An optical fiber includes a silica-based glass. The optical fiber includes a core, an optical cladding surrounding the core, and a physical cladding surrounding the optical cladding. The optical cladding includes a first region in contact with the core and surrounding the core. A photosensitive material is added to the core and the first region. A concentration of the photosensitive material in the first region is 30% or more of a concentration of the photosensitive material in the core. A value obtained by integrating a light intensity of an LP.sub.01 mode at a wavelength of 1310 nm in a region added with the photosensitive material is 87% or more of a value obtained by integrating the light intensity in an entire region of the optical fiber.

An optical fiber device may include a core including a primary section and a secondary section. The secondary section may include at least one insert element inserted within the primary section at an off-center location with respect to a center of the primary section. The secondary section may twist about an axis of the optical fiber device along a length of the optical fiber device. A rate of twist at which the secondary section twists about the axis may increase from a first end of the optical fiber device toward a second end of the optical fiber device. The secondary section being twisted about the axis may cause an optical beam, launched at the first end of the optical fiber device, to be at least partially converted to a rotary optical beam at the second end of the optical fiber device.

A method of fabricating a variable diameter fiber includes providing a fiber optic cable comprising a cladding region, a fiber core, and a plurality of sacrificial regions disposed in the cladding region and focusing a laser beam at a series of predetermined locations inside the fiber optic cable. The method also includes creating a series of damage sites associated with the series of predetermined locations, wherein the series of damage sites define a variable diameter profile and a latticework in the cladding region of the fiber optic cable. The method further includes exposing the fiber optic cable to an etchant solution, preferentially etching the series of damage sites, and separating peripheral portions of the fiber optic cable to release the variable diameter fiber.

The present disclosure provides a method for modification of surface of an initial optical fiber preform. The initial optical fiber preform is manufactured using at least one preform manufacturing process. The surface of the initial optical fiber preform is treated with 50-70 liters of chlorine per square meter of the surface of the initial optical fiber preform. The surface of the initial optical fiber preform is flame polished using a flame polishing module. The treatment of the surface of the initial optical fiber preform with chlorine and flame polishing of the surface of the initial optical fiber preform collectively converts the initial optical fiber preform into a modified optical fiber preform.

A mounting surface defines a branching channel, the branching channel having a main channel and one or more sub-channels branching off the main channel. An optic fiber is affixed to the mounting surface, the optic fiber including a cladding layer and an interior surrounded by the cladding layer, wherein part of the optic fiber is suspended over the main channel. A clad light stripper includes one or more discontinuities in an outer surface of the cladding layer of a suspended section of the optic fiber, the one or more outer surface discontinuities to release a portion of the process light. The one or more subchannels include a first sub-channel having an ingress located to capture released light from an individual one of the one or more discontinuities and trap at least a portion thereof.

A wear sensing liner for a comminution apparatus. The wear sensing liner comprising: a liner body comprising; a wear surface side defining a wear surface; and an opposed, operatively rear surface side; and at least one sensor carried by the liner body. The at least one sensor being carried by the liner body to sense wear of the wear surface side of the liner body. The at least one sensor being configured to degrade in response to wear of the wear surface side of the liner body and to output a signal representative of the wear of the wear surface side of the liner body.