An optical combiner 3 includes a plurality of incoming optical fibers 10, an outgoing optical fiber 20, and a plurality of bridge fibers 60, 50 provided between the plurality of incoming optical fibers 10 and the outgoing optical fiber 20, the plurality of bridge fibers 60, 50 being optically coupled to each other. In the bridge fibers 60, 50, a ratio of the outer diameter of a core 61, 51 to the outer diameter of a cladding 62, 52 is smaller in a bridge fiber located more apart from the incoming optical fiber 10.

An electro-optical assembly comprises a substrate having a support-surface, and a photonic integrated circuit (PIC) mounted with a contact surface on the support-surface. The (PIC) comprises an integrated optical waveguide structure defining at least two waveguide end faces, at an edge surface of the PIC, perpendicular to its contact surface, and forming optical ports. An optical coupling device, mounted with a contact surface on the support-surface, optically connects at least two optical fibers to the PIC and comprises an optical waveguide structure-defining at least two front waveguide end faces provided at a front edge surface thereof, perpendicular to its contact surface. The number of front waveguide end faces corresponds to the number of the waveguide end faces. The optical coupling device is positionable during an active positioning process to align the respective waveguide end faces. A method of manufacturing such an electro-optical assembly is also provided.

An object is to provide an optical communication system capable of controlling the output ratio by port and by wavelength for incident light of different wavelengths, a method of determining the split ratio of an uneven-split optical splitter for controlling the output ratio by port and by wavelength, and a transmission range determination method for the optical communication system. The split ratio determination method for an uneven-split optical splitter according to the present invention uses the melt-draw distance to adjust the split ratio of each fiber-optic splitter included in the uneven-split optical splitter such that the light output from the farthest ONUs among each of the ports connected under the ports B to M of the uneven-split optical splitter arrives with the minimum reception sensitivity at OLT receivers in a PON system.

A capillary combiner housing for an optical fiber combiner has an inner combiner casing supporting optical fibers. The capillary combiner housing includes a non-metallic body defining a lumen between an input side and an output side, the lumen sized to receive the inner combiner casing, the non-metallic body having a coefficient of thermal expansion substantially matching that of the inner combiner casing. Also included is a first aperture in the input side, the first aperture having a first inside diameter sized to receive multiple input optical fibers, and a second aperture in the output side, the second aperture having a second inside diameter sized to receive an output fiber.

A method for forming a side-pumped optical fiber combiner includes ablating a cladding of a signal fiber to form an angled notch in the cladding. The signal fiber includes a core and the cladding surrounding the core. The method further includes inserting a cladding-free end of a pump fiber into the angled notch. The pump fiber includes a core and a cladding, the cladding-free end including the core of the pump fiber and free from the cladding of the pump fiber. The method further includes fusing the cladding-free end to the signal fiber.

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.

There is described an optical fiber coupler generally having: a first optical fiber having a longitudinally extending multimode guiding region and a first taper portion longitudinally extending between first and second locations of the first optical fiber, the first taper portion having a dimension progressively decreasing along a first taper direction from the first location to the second location; a second optical fiber having a longitudinally extending multimode guiding region and a second taper portion longitudinally extending between third and fourth locations of the second optical fiber, the second taper portion having a dimension progressively decreasing along a second taper direction from the third location to the fourth location; and a coupling region where at least a portion of the first taper portion is optically coupled to a portion of the second taper portion, with the first and second taper directions being opposite to one another.

An electro-optic beam controller, material processing apparatus, or optical amplifier, and corresponding methods, can include an actively controlled, waveguide-based, optical spatial mode conversion device. The conversion device can include a coupler, which can be a photonic lantern, configured to combine light beams into a common light beam; a sensor configured to measure at least one characteristic of the common light beam; and a controller configured to modulate optical parameters of the individual, respective light beams to set one or more spatial modes of the common light beam. Actively controlled and modulated devices can be used to maintain a stable, diffraction-limited beam for use in an amplification, communications, imaging, laser radar, switching, or laser material processing system. Embodiments can also be used to maintain a fundamental or other spatial mode in an optical fiber even while scaling to kilowatt power.

The invention concerns an apparatus and its use for laser processing. The invention also concerns a method and an optical component. According to the invention, at a first laser device, providing a first optical feed fiber and a second laser device providing a second optical feed fiber is provided. A beam combining means connected to the first and second feed fibers and to a multi-core optical fiber is adapted to form a composite laser beam by having the first optical feed fiber aligned with a first core of the multi-core optical fiber and the second optical feed fiber aligned with at least one second core of the multi-core optical fiber. The first and second cores outputs a composite laser beam to a workpiece to be processed. A control unit controls power density of at least one of first and second laser beams of the composite laser beam in at least one of: in response to approaching a change point in direction of cutting progression and to cause change in relation between the power density of the first output laser beam and power density of the second output laser beam in accordance with thickness of the workpiece being cut.

A combiner includes: an input fiber bundle including input fibers; and a bridge fiber including a GI fiber section. A beam bundle emitted from the input fiber bundle enters the GI fiber section, the bridge fiber has a diameter smaller at an exit end surface of the bridge fiber than at an entrance end surface of the bridge fiber, and the GI fiber section converges the beam bundle.