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.

An optical fiber combiner comprises a double-clad fiber (DCF) and one or more multimode fibers (MMFs). DCF comprises a transition portion, a DCF taper portion, and an output section coupling to the DCF taper portion, whereas each of-_MMFs comprises an MMF taper configured to be fused around-_DCF in the transition portion. MMFs are configured to carry a combined optical energy (COE) and to couple to DCF. COE passes through the MMF taper with larger divergence of higher-order modes generated and coupled into-_DCF, whereas the DCF taper portion can partially offset the larger divergence. COE coupled, when traced through the output section, emerges in the air with a smaller output beam divergence of the higher-order modes, thereby preserving some of the higher-order modes in the output section and increasing a coupling efficiency of COE coupled from-_MMFs to-_DCF with improved thermal performance.

An optical fiber combiner comprises a double-clad fiber (DCF) and one or more multimode fibers (MMFs). DCF comprises a transition portion, a DCF taper portion, and an output section coupling to the DCF taper portion, whereas each of MMFs comprises an MMF taper configured to be fused around DCF in the transition portion. MMFs are configured to carry a combined optical energy (COE) and to couple to DCF. COE passes through the MMF taper with larger divergence of higher-order modes generated and coupled into DCF, whereas the DCF taper portion can partially offset the larger divergence. COE coupled, when traced through the output section, emerges in the air with a smaller output beam divergence of the higher-order modes, thereby preserving some of the higher-order modes in the output section and increasing a coupling efficiency of COE coupled from MMFs to DCF with improved thermal performance.

The present disclosure generally relates to devices, which may be used in communication or optoelectronic modules for example, suitable for arrayed positioning of a plurality of fiber optical components. In one form, an optoelectronic module includes a printed circuit board (PCB) and at least one optical component array device including an array of laterally or radially spaced receptacles configured to receive an optical component. One or more of the receptacles includes a fused fiber optical component positioned therein. A recursive fiber may extend between an output of a first fused fiber optical component and an input of a second fused fiber optical component, and an optical fiber routing member may be coupled to the PCB and include a plurality of guides extending away from the PCB and defining a pathway for routing optical fibers relative to the PCB.

In some implementations, a fiber optic combiner may comprise an enclosing tube having a geometric shape and multiple optical fibers bundled within the enclosing tube. In some implementations, the multiple fibers comprise at least one optical fiber having a core and a non-circular cladding surrounding the core. The non-circular cladding may cause the multiple optical fibers to have a larger tube fill factor and a lower expected beam parameter product increase factor relative to the multiple optical fibers all having circular claddings.

An optical combiner includes: an optical fiber bundle formed by a plurality of first optical fibers; and a second optical fiber including an end surface joined to an end surface of the optical fiber bundle by fusion-splicing. The plurality of first optical fibers includes a predetermined first optical fiber and other first optical fibers. The predetermined first optical fiber is composed of one or more materials having higher softening temperatures than one or more materials of the other first optical fibers.

A fused fibre coupler comprising: a single mode fibre, SMF, and an orbital angular momentum fibre, OAMF, the fibres having a coupling portion in which the fibres are longitudinally aligned side by side and fused at least over a coupling length in which the SMF and OAMF are tapered such that the diameter of the SMF and the diameter of the OAMF give the fibres matching effective refractive indices for a single mode of the SMF and an orbital angular momentum, OAM, mode of the OAMF for a coupled wavelength of light.

Provided is an optical fiber coupler capable of suppressing variation of polarization state of light passing through a coupler portion. The optical fiber coupler includes: a substrate having a groove; a coupler portion which is inserted into the groove and to which a middle portion of each of optical fibers is joined; and an adhesive for bonding the coupler portion to the substrate. Shore D hardness of the adhesive is 10 to 35. By setting the Shore D hardness of the adhesive to 10 to 35, it is possible to suppress the variation of the polarization state of the light passing through the coupler portion.

To provide an optical branch coupler which facilitates communizing the design of an optical transmission path, the optical branch coupler comprising: a first add drop unit for outputting a third optical signal to a first line in which a first optical signal received from the first line and a second optical signal inserted into the first line are multiplexed and outputting the first optical signal; and a second add drop unit for receiving the first optical signal, receiving a sixth optical signal from a second line different from the first line in which a fourth optical signal and a fifth optical signal dropped from the second line are wavelength multiplexed, demultiplexing the fourth and fifth optical signals, and outputting a seventh optical signal to the second line in which the fourth optical signal and the first optical signal transmitted by the first add drop unit are multiplexed.

There is described a multi-clad optical fiber for propagating an optical signal having at least a single mode. The multi-clad optical fiber generally has a fiber core, an inner cladding surrounding the fiber core, and at least an outer cladding surrounding the inner cladding, the multi-clad optical fiber having at least a taper portion extending along a longitudinal dimension z, the taper portion having a radial dimension progressively decreasing at a normalized slope exceeding an adiabaticity criterion of a conventional single-clad optical fiber propagating at least the single-mode across its single-mode core.