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.

Provided is a system for and a method of processing an optical fiber, such as tapering an optical fiber. The method includes receiving fiber parameters defining characteristics of an optical fiber, modeling an idealized fiber based on the fiber parameters to establish modeled data, and establishing processing parameters. A processing operation is performed on the optical fiber according to the processing parameters to produce a resultant fiber. Aspects of the resultant fiber are measured to establish measured data. The measured data and the modeled data are normalized to a common axis and a difference between the two is determined. The processing parameters are adjusted based on the differences.

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.

A high-power Raman fiber laser includes: a seed laser; a plurality of pump lasers, each including a cladding and comprising of thulium-doped fiber laser (TDFL) and configured to operate in a 1935-2020 nm spectral window; a pump/seed combiner to combine outputs of the pump lasers and output of the seed laser and having a tapered portion including a cladding; and a Raman fiber amplifier having a core and a cladding surrounding the core, the seed laser is launched into the core, and pump laser output beams are launched into the cladding, to amplify the seed laser to produce an amplified output signal, and a brightness of the cladding of the Raman fiber amplifier is matched to a combined brightness of the plurality of pump lasers.

An apparatus configured to function as a pluggable single-wavelength bidirectional transceiver in a switching network. The apparatus includes: a 21 fusion coupler; an input/output optical fiber, a detector optical subassembly (OSA) fiber and a laser OSA fiber all connected to the 21 fusion coupler; and a transceiver that includes a transceiver electronic circuit printed wiring board (PWB) and laser and detector OSAs electrically coupled to the transceiver electronic circuit PWB. The laser OSA includes a laser that is situated to transmit light to the laser OSA fiber, while the detector OSA includes a photodetector that is situated to receive light from the detector OSA fiber. The transceiver electronic circuit PWB also includes a multiplicity of transceiver input/output metal contacts arranged at one pluggable end of the PWB.

A coating removal tool includes a base part and a cover part, to remove a coating of an optical fiber by overlapping the cover part and the base part. The base part and the cover part are made of resin, and include at least a pair of coating removal blades including a base front blade portion provided on the base part and a cover front blade portion provided on the cover part. The base part includes a V-groove which sandwiches the optical fiber in either one or both of a front and rear of the optical fiber in the longitudinal direction and the cover part includes a V-groove which sandwiches the optical fiber and is provided on a side where the V-groove exists in the front and rear of the longitudinal direction in a state where the cover part and the base part are overlapped.

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.

An illumination device includes at least four narrow band light sources, primary light combiners that combine narrow band light from at least two of the narrow band light sources, and a secondary light combiner that combines primary combined light combined by the primary light combiners. The device is configured to radiate, as illumination light, secondary combined light combined by the secondary light combiner. The light sources are grouped into groups based on illumination characteristics of the narrow band light so that light sources satisfying a condition for the illumination characteristics are grouped into the same group. The light sources in the same group are connected to the primary light combiners so that the light sources in the same group are distributed to the primary light combiners.

An all-fiber laser oscillator comprises a laser cavity, an amplification fiber, a plurality of diode lasers, and at least one side-pump signal-and-pump combiner (combiner). The combiner comprises a double-clad fiber (DCF) and four or more multimode fibers (MMFs). DCF comprises a first taper portion, whereas each of MMFs comprises a second taper portion fused around DCF. MMFs are configured to carry a portion of combined optical energy (COE) and to couple to DCF. The first taper portion can partially compensate a beam divergence created by the second taper portion, thereby increasing a coupling efficiency of COE coupled from MMFs to DCF with improved thermal performance. In a coupling portion, a refractive index difference between MMFs and DCF is configured to form a backward coupling barrier to suppress an optical energy in DCF from coupling into MMFs, thereby protecting the plurality of diode lasers from damage.

Provided is a system for and a method of processing an optical fiber, such as tapering an optical fiber. The method includes receiving fiber parameters defining characteristics of an optical fiber, modeling an idealized fiber based on the fiber parameters to establish modeled data, and establishing processing parameters. A processing operation is performed on the optical fiber according to the processing parameters to produce a resultant fiber. Aspects of the resultant fiber are measured to establish measured data. The measured data and the modeled data are normalized to a common axis and a difference between the two is determined. The processing parameters are adjusted based on the differences.