An optical module according to an embodiment includes a first optical component and a second optical component including a multicore fiber (MCF) and a spatial joining part. The first optical component includes a first uncoupled MCF having small optical coupling between cores and a first coupled MCF having a mode field diameter (MFD) larger than a MFD of the first uncoupled MCF. The second optical component includes a second uncoupled MCF having small optical coupling between cores and a second coupled MCF having a MFD larger than a MFD of the second uncoupled MCF. In the first coupled MCF and the second coupled MCF, crosstalk is periodically produced along the length direction of an MCF, and the total of the length of the first coupled MCF and the length of the second coupled MCF is a length L in which crosstalk is suppressed.

The present disclosure relates to an optical fiber having a core and a cladding, where the cladding is doped with a dopant. The cladding has a dopant concentration gradient in the radial direction such that a concentration of the dopant changes with respect to radial distance from a core-cladding interface. Doping the cladding of the optical fiber enables ablation of the fiber surface with a line source to provide an ablated wedge or crack such that cleaving can be achieved by applying a stress force to the fiber after ablation or by applying a pull force during ablation.

An optical part includes: an optical fiber having a core portion and a cladding portion that is formed around the core portion; a light absorber placed around the optical fiber; and an adhesive member that adheres the light absorber and the optical fiber to each other. Further, the cladding portion includes: a main portion extending along a longitudinal direction and having a main portion cladding diameter; and an input end portion positioned closer to a light input side with respect to the main portion, and an input end face cladding diameter at an input end face of the input end portion is less than the main portion cladding diameter.

Fiber optic tapered coupler and methods of manufacturing same. One method of manufacturing a fiber optic tapered coupler arrangement includes providing an output fiber having a first end and a second end opposite the first end. The method also includes applying heat to the first end of the output fiber, wherein the first end expands forming a taper at the first end of the output fiber. The method also includes splicing the tapered first end of the output fiber to a first end of an input fiber, wherein a non-tapered portion of the output fiber has a first diameter and the input fiber has a second diameter different from the first diameter.

A beam combiner includes: a plurality of input optical fibers, a beam combination optical fiber and an output optical fiber; the input optical fiber includes an input fiber core and an optical fiber input cladding layer wrapping an outer wall of the input fiber core, the output optical fiber includes an output fiber core and an optical fiber output cladding layer wrapping an outer wall of the output fiber core, a cross section of the optical fiber input cladding layer is fan-shaped or hexagonal and is provided with a groove and/or a protrusion along an axial direction, the plurality of input optical fibers are nested with each other to form the beam combination optical fiber, fiber cores in the beam combination optical fiber are all connected to the output fiber core, and a beam combination cladding layer of the beam combination optical fiber is connected to the output fiber core.

A method for manufacturing an optical fiber includes: exposing a glass fiber by stripping a fiber coating layer at an end portion, on a splicing side, of each of a pair of optical fibers; fusion-splicing the glass fibers; and recoating a protective resin on a periphery of exposed portions of the glass fibers. The fiber coating layer includes a primary resin layer on an inner peripheral side and having a Young's modulus of 0.5 MPa or less and a secondary resin layer on an outer peripheral side and having a Young's modulus of 800 MPa or greater, the exposing includes forming a shape of a coating edge of the fiber coating layer which includes the primary resin layer and the secondary resin layer into a tapered shape which becomes narrower toward the end portion side, and the recoating includes coating the protective resin to include the coating edge.

Improved optical interconnects obtained by replacing one or more single core fibers with one or more multicore fibers. In some instances, at least one of the optical fibers is shaped.

Improved optical interconnects obtained by replacing one or more single core fibers with one or more multicore fibers. In some instances, at least one of the optical fibers is shaped.

A miniature diaphragm-based fiber-optic tip FP pressure sensor, and fabrication method and application thereof. A miniature diaphragm-based fiber-optic tip FP pressure sensor includes an optical fiber, a hollow-core optical fiber, and a pressure sensing diaphragm, wherein the optical fiber and the hollow-core optical fiber have the same diameter, the two are spliced by arc welding; and the pressure sensing diaphragm is bonded to the endface of the hollow-core optical fiber by hydroxide catalysis bonding. The FP pressure sensor can not only realize the all-silica structure of a sensor, but also make the joint of each component free of organic polymer, and has extremely high long-term stability and thermal stability. Meanwhile, by means of a fabrication method of the miniature diaphragm-based fiber-optic tip FP pressure sensor, the application range and service life of the sensor are increased, and fabrication costs are reduced.

A hollow-core photonic crystal fiber (HC-PCF) (10) for guiding at least one mode of a light field (1) along a mode guiding section (11) of the HC-PCF (10), comprises an outer jacket (12), an inner cladding (13) and a hollow core (14), which extend along the HC-PCF (10), wherein the inner cladding (13) is arranged on an interior surface of the outer jacket (12) and comprises anti-resonant structures (15) surrounding the hollow core (14), and the hollow core (14) has a mode guiding core diameter (d) provided along the mode guiding section of the HC-PCF (10), and wherein at least one fiber end (16) of the HC-PCF (10) has a light field coupling section (17) in which the hollow core (14) is tapered over an axial coupling section length from a fiber end core diameter (D) at the at least one fiber end (16) to the mode guiding core diameter (d). Furthermore, methods of using the HC-PCF and manufacturing the HC-PCF are described.