There is provided a method of manufacturing an optical connector, including: preparing a multi-core optical fiber including a glass fiber and a resin coating that covers the glass fiber; inserting the glass fiber exposed from the resin coating into the ferrule such that the glass fiber protrudes from an end surface of a ferrule by a length A; rotating and aligning the multi-core optical fiber with respect to the ferrule; fixing the multi-core optical fiber to the ferrule; and so as to scrap off a tip end of the ferrule by a length. A deviation angle in the circumferential direction between a first initial end surface of the one end of the prepared glass fiber and a cross section of the glass fiber separated from the initial end surface by a length A+B mm is equal to or less than 0.9?.

There is provided a method to fabricate optical taps and waveguide devices in photonic crystal fibers and other fibers with hollow structures. The method involves a preparation step, where the hollow holes inside the fiber are collapsed or partially modified locally; and a waveguide fabrication step, where a femtosecond laser is focused inside the fiber and used to produce optical waveguides that interact in the region that was previously modified in the preparation step.

Techniques are described for using confinement structures and/or pattern gratings to reduce or prevent the wicking of sealant polymer (e.g., glue) into the optically active areas of a multi-layered optical assembly. A multi-layered optical structure may include multiple layers of substrate imprinted with waveguide grating patterns. The multiple layers may be secured using an edge adhesive, such as a resin, epoxy, glue, and so forth. A confinement structure such as an edge pattern may be imprinted along the edge of each layer to control and confine the capillary flow of the edge adhesive and prevent the edge adhesive from wicking into the functional waveguide grating patterns of the layers. Moreover, the edge adhesive may be carbon doped or otherwise blackened to reduce the reflection of light off the edge back into the interior of the layer, thus improving the optical function of the assembly.

An object of the present invention is to provide a structure of an optical fiber capable of satisfying desired requirements of an output power, a propagation distance, and a beam quality. In the design of the PCF of the present invention, the PCF has air holes having diameters d and intervals in an overlapping region where a region of A.sub.eff of a desired value or more and a cutoff region in a desired higher-order mode overlap each other on a graph where the horizontal axis represents d/ and the vertical axis represents , so that it is possible to sufficiently cut off the mode which is the desired higher-order mode or more, and thus, it is possible to select a region where the A.sub.eff is large.

Disclosed is an optical fiber including a plasmonic optical filter with a closed curved shape provided at, at least portion thereof. A method of manufacturing the plasmonic optical filter includes a step of exposing a core, a step of forming a thin metal film on the core through physical vapor deposition while rotating the core in a circumferential direction after changing a rotation axis of the core, and a step of patterning nanopatterns on the cylinder-shaped thin metal film using focused ion beam technique assisted with endpoint detection method. Due to such constitutions, an active area to generate an optical signal for optical sensor can be increased.

An apparatus for sensing pressure and temperature includes: a hollow glass tube; a first optical fiber having an end disposed into a first end of the tube; a second optical fiber being disposed in a second end of the tube, the second optical fiber having a first solid core section followed by a hollow core section followed by a second solid core section, a first gap formed between the first and second optical fibers, a length of the first solid core section forming a second gap, and a length of the hollow core section forming a third gap; an optical interrogator that transmits light at various wavelengths and measures an intensity of reflected light due to the first gap, second gap, and third gap as a function of frequency to provide interrogation data; and a processor that matches the interrogation data to reference data to estimate the pressure and/or temperature.

Techniques are described for using confinement structures and/or pattern gratings to reduce or prevent the wicking of sealant polymer (e.g., glue) into the optically active areas of a multi-layered optical assembly. A multi-layered optical structure may include multiple layers of substrate imprinted with waveguide grating patterns. The multiple layers may be secured using an edge adhesive, such as a resin, epoxy, glue, and so forth. A confinement structure such as an edge pattern may be imprinted along the edge of each layer to control and confine the capillary flow of the edge adhesive and prevent the edge adhesive from wicking into the functional waveguide grating patterns of the layers. Moreover, the edge adhesive may be carbon doped or otherwise blackened to reduce the reflection of light off the edge back into the interior of the layer, thus improving the optical function of the assembly.

A feedstock line (100) comprises elongate filaments (104), a resin (124), and optical direction modifiers (123). The resin (124) covers the elongate filaments (104). The optical direction modifiers (123) are covered by the resin (124) and are interspersed among the elongate filaments (104). Each of the optical direction modifiers (123) has an outer surface (184). Each of the optical direction modifiers (123) is configured such that when electromagnetic radiation (118) strikes the outer surface (184) from a first direction, at least a portion of the electromagnetic radiation (118) departs the outer surface (184) in a second direction that is at an angle to the first direction to irradiate, in the interior volume of the feedstock line (100), the resin (124) that, due at least in part to the elongate filaments (104), is not directly accessible to the electromagnetic radiation (118), incident on the exterior surface of the feedstock line.

Disclosed is an optical fiber including a plasmonic optical filter with a closed curved shape provided at, at least portion thereof. A method of manufacturing the plasmonic optical filter includes a step of exposing a core, a step of forming a thin metal film on the core through physical vapor deposition while rotating the core in a circumferential direction after changing a rotation axis of the core, and a step of patterning nanopatterns on the cylinder-shaped thin metal film using focused ion beam technique assisted with endpoint detection method. Due to such constitutions, an active area to generate an optical signal for optical sensor can be increased.

An optical fiber includes a core (30) and a cladding (32) surrounding the core. One or more indentations (42) extend into the fiber from outside of the core. The indentations desirably extend into the core and desirably define surfaces (44) transverse to the axis (36) of the fiber and extending into the core. A solid filler material (52) desirably is disposed within the indentations. The indentations and filler facilitate extraction of light from the core. The fiber desirably is a polymeric multimode fiber.