An antifouling layer stack comprising a first layer element, a silicone layer, and a second layer element. The silicone layer is a light guide for UV radiation, and may include embedded UV light sources. The first layer element is situated on a first surface of the silicone layer, and the second layer element is situated on a second surface of the silicone layer. The first and second layer elements differ in composition from the silicone layer. The first layer element facilitates transmission of the UV radiation from the silicone layer to an external medium, and may provide protection and improve the structural integrity of the stack. The second layer element may also provide protection and structural integrity. The second layer element may be reflective, and may provide an adhesive surface for attaching the stack to a vessel.

The present disclosure relates to methods of forming a fiber optic core, and a fiber optic component with a highly uniform cladding covering the fiber optic core. In one microfabrication process a first sacrificial tubing is provided which has a predetermined inner diameter. A quantity of a curable polymer is also provided. The first sacrificial tubing is at least partially filled with the curable polymer. The curable polymer is then cured. The first sacrificial tubing is then removed to produce a finished fiber optic core. Additional operations may be performed by which the fiber optic core is placed inside a thermoplastic tubing, which is itself placed inside a sacrificial heat shrink. Heat is applied to reflow the thermoplastic tubing around the fiber optic core, thus forming a highly uniform thickness cladding. When the sacrificial heat shrink tubing is removed a finished fiber optic component is present. Additional microfabrication methods are disclosed which involve dip coating a pre-formed fiber optic core in a polymer, and then curing the polymer to form a finished fiber optic component with a uniform thickness cladding.

Provided is an optical connector that includes a ferrule and an optical fiber as a plastic optical fiber. The ferrule has a leading end face and a through hole for holding a fiber, the through hole having an opening end in the leading end face. The optical fiber has a leading end. The leading end of the optical fiber is inserted in the through hole and located at a retraction position retracted from the leading end face.

Some embodiments may include a packaged laser diode assembly, comprising: a length of optical fiber having a core and a polymer buffer in direct contact with the core, the length of optical fiber having a first section and a second section, the first section of the length of optical fiber including a tip of an input end of the optical fiber, wherein the polymer buffer covers only the second section of the first and second sections; one or more laser diodes to generate laser light; means for directing a beam derived from the laser light into the input end of the length of optical fiber; a light stripper attached to the core in the first section of the length of optical fiber. Other embodiments may be disclosed and/or claimed.

[Problem] To provide a radiation curable resin composition that is suitable as a primary material of an optical fiber and has a fast curing rate by irradiation with radiation.

[Solution] A radiation polymerizable composition for forming a primary coating layer of an optical fiber, the radiation polymerizable composition comprising: (A) a urethane oligomer comprising a structure represented by formula (I) below:

##STR00001## wherein R is a vinyl group and * is a bond; (B) one or more compounds of: (i) maleic anhydride, (ii) a compound represented by formula (II):

##STR00002## wherein R.sup.1 is a single bond or an alkanediyl group comprising 1 to 6 carbon atoms, and R.sup.2 is a hydrogen atom, a hydroxy group, or a group represented by predetermined formula (II-1) or formula (II-2), or (iii) a compound represented by formula (III):

##STR00003## wherein R.sup.5 is an alkanediyl group comprising 1 to 6 carbon atoms; and (C) a radiation polymerization initiator.

A terahertz polarization beam splitter based on a two-core negative curvature fiber is provided, which relates to the technical field of optical fiber communication. The polarization beam splitter includes: a base circular tube and core separation structures. Multiple large cladding tubes are internally tangent and connected to an inner wall of the base circular tube and arranged at equal intervals along a circumference of the inner wall of the base circular tube, and the multiple large cladding tubes are symmetrically distributed on the inner wall of the base circular tube. Embedded circular tubes are internally tangent and connected to inner walls of the multiple large cladding tubes respectively. The core separation structures are two in number.

A system for producing a multicore optical fiber includes a source of electromagnetic radiation in a spectral range that is suitable for inducing photopolymerization of a transparent polymer. An arrangement of one or more optical components is configured to concurrently focus the radiation that is emitted by the source on a plurality of elongated regions of the transparent polymer so as to photopolymerize the transparent polymer solely in the elongated regions to increase the index of refraction of the elongated regions such that in the optical fiber that is formed of the transparent polymer after the elongated regions are photopolymerized, each of the elongated regions functions as a core of the optical fiber and regions of the transparent polymer that surround the elongated regions function as a cladding of each of the cores.

The glass-based THz optical waveguides (10) disclosed herein are used to guide optical signals having a THz frequency in the range from 0.1 THz to (10) THz and include a core (20) surrounded by a cladding (30). The core has a diameter D1 in the range from (30) μm to 10 mm and is made of fused silica glass having a refractive index n.sub.1. The cladding is made of either a polymer or a glass or glass soot and has a refractive index n.sub.2<n.sub.1 and an outer diameter D2 in the range from 100 μm to 12 mm. The THz optical waveguides can be formed using processes that are extensions of either fiber, ceramic and soot-based technologies. In an example, the THz waveguides have a dielectric loss D.sub.f<0.005 at 100 GHz.

A method of making an optical fiber sensor device for distributed sensing includes generating a laser beam comprising a plurality of ultrafast pulses, and focusing the laser beam into a core of an optical fiber to form a nanograting structure within the core, wherein the nanograting structure includes a plurality of spaced nanograting elements each extending substantially parallel to a longitudinal axis of optical fiber. Also, an optical fiber sensor device for distributed sensing includes an optical fiber having a longitudinal axis, a core, and a nanograting structure within the core, wherein the nanograting structure includes a plurality of spaced nanograting elements each extending substantially parallel to the longitudinal axis of the optical fiber. Also, a distributed sensing method and system and an energy production system that employs such an optical fiber sensor device.

An expanded beam connector has a MOST ferrule; a fiber to be retained within the MOST ferrule; and, a collimating lens abutting the fiber for expanding the optical beam of the fiber wherein the lens and fiber are in alignment to a common optic axis. In one embodiment, the collimating lens can have a conical cutout configured to aid in aligning the fiber to the common optic axis. In another embodiment, the collimating lens can have a semi-cylindrical tab protruding from the rear with a V-groove configured to interact with a flexible feature on the interior of the ferrule to align the fiber to the common optic axis.