Abstract: A multicore fiber (MCF) optical attenuator (MCF-ATT) can be configured to attenuate light traveling from at least one core of a first MCF to at least one core of a second MCF at least at one wavelength W?1. The MCF-ATT can include a plurality of optical waveguides and an attenuating section within the plurality of optical waveguides. The attenuating section can include a distorted portion of the plurality of optical waveguides. The distorted portion can be configured to couple at least one propagating optical mode with at least one radiation mode at the wavelength W?1.

Abstract: A multichannel optical coupler array can include a coupler housing structure and longitudinal waveguides. At least one of the longitudinal waveguides can be a vanishing core waveguide having an inner vanishing core having a first refractive index (N-1), an outer core having a second refractive index (N-2), and an outer cladding having a third refractive index (N-3). A refractive index transition between N-1 and N-2 can have a function form N(r), where r is a transverse distance from the inner vanishing core center. The function N(r) can be a smooth function having a positive average of the second derivative or function N(r) can be a step function with at least one step approximating the smooth function. The coupler housing structure may have non-circular holes formed by convex-shaped housing structure elements.

Abstract: A multichannel optical coupler array can include a coupler housing structure and longitudinal waveguides. At least one of the longitudinal waveguides can be a vanishing core waveguide having an inner vanishing core having a first refractive index (N-1), an outer core having a second refractive index (N-2), and an outer cladding having a third refractive index (N-3). A refractive index transition between N-1 and N-2 can have a function form N(r), where r is a transverse distance from the inner vanishing core center. The function N(r) can be a smooth function having a positive average of the second derivative or function N(r) can be a step function with at least one step approximating the smooth function. The coupler housing structure may have non-circular holes formed by convex-shaped housing structure elements.

Abstract: Wavelength division multiplexers for space division multiplexing can include wavelength division multiplexing fanout devices or pump-signal combiners for multicore fibers.

Abstract: Space division multiplexers can include adapters between multicore fibers with different core patterns and/or add-drop multiplexers for multicore fibers.

Abstract: A multichannel optical coupler array can include a coupler housing structure and longitudinal waveguides. At least one of the longitudinal waveguides can be a vanishing core waveguide having an inner vanishing core having a first refractive index (N-1), an outer core having a second refractive index (N-2), and an outer cladding having a third refractive index (N-3). A refractive index transition between N-1 and N-2 can have a function form N(r), where r is a transverse distance from the inner vanishing core center. The function N(r) can be a smooth function having a positive average of the second derivative or function N(r) can be a step function with at least one step approximating the smooth function. The coupler housing structure may have non-circular holes formed by convex-shaped housing structure elements.

Abstract: An optical coupler array can include an elongated optical element having a coupler housing structure and at least one longitudinal waveguide embedded in said housing structure. The housing structure can have an outer cross sectional shape comprising a first side comprising one or more curved portions and a second side comprising one or more flat portions. The second side can be disposed at a distance from the at least one longitudinal waveguide such that waveguiding properties are preserved and not disturbed.

Abstract: Space division multiplexers can include adapters between multicore fibers with different core patterns and/or add-drop multiplexers for multicore fibers.

Abstract: An optical fiber connector configured to rotationally align a first optical fiber with a second optical fiber is provided. The connector can include at least two rotational alignment features. At least one of the two rotational alignment features can include at least one ferrule configured to hold at least the first optical fiber.

Abstract: An optical fiber connector configured to rotationally align a first optical fiber with a second optical fiber is provided. The connector can include at least two rotational alignment features. At least one of the two rotational alignment features can include at least one ferrule configured to hold at least the first optical fiber.

Abstract: A multichannel optical coupler can include an output optical coupler array and a plurality of optical fibers. At least two of the plurality of optical fibers can be connected together at an end opposite the output optical coupler array.

Abstract: The optical fiber coupler array can be capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array can be configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing. Advantageously, the refractive indices and sizes of both inner and outer core, and/or other characteristics of vanishing core waveguides in the optical coupler array can be configured to reduce the back reflection for light propagating from the plurality of the optical fibers at the coupler first end to the optical device at the coupler second end, and/or vice versa.

Abstract: Advantageously, at least one embodiment of the present disclosure comprises a polarization maintaining PROFA (“PM-PROFA”) coupler in which the polarization axes of the individual vanishing core waveguides thereof are oriented or aligned without the need to adjust the orientation of each individual VC waveguide.

Abstract: The optical fiber coupler array can be capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array can be configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing. Advantageously, the refractive indices and sizes of both inner and outer core, and/or other characteristics of vanishing core waveguides in the optical coupler array can be configured to reduce the back reflection for light propagating from the plurality of the optical fibers at the coupler first end to the optical device at the coupler second end, and/or vice versa.

Abstract: The inventive optical fiber coupler array is capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array is configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing. The novel optical coupler array includes a plurality of waveguides (at least one of which may optionally be polarization maintaining), that comprises at least one gradually reduced vanishing core fiber, at least in part embedded within a common housing structure. Alternatively, the novel coupler array may be configured for utilization with at least one of an optical fiber amplifier and an optical fiber laser.

Abstract: An optical coupler array can include an elongated optical element having a coupler housing structure and at least one longitudinal waveguide embedded in said housing structure. The housing structure can have an outer cross sectional shape comprising a first side comprising one or more curved portions and a second side comprising one or more flat portions. The second side can be disposed at a distance from the at least one longitudinal waveguide such that waveguiding properties are preserved and not disturbed.

Abstract: An optical coupler array can include an elongated optical element having a coupler housing structure and at least one longitudinal waveguide embedded in said housing structure. The housing structure can have an outer cross sectional shape comprising a first side comprising one or more curved portions and a second side comprising one or more flat portions. The second side can be disposed at a distance from the at least one longitudinal waveguide such that waveguiding properties are preserved and not disturbed.

Abstract: The inventive circular chiral fiber polarizer is operable to convert linearly polarized light to circularly polarized light, may be advantageously fabricated in an “in-fiber” manner and to comprise desirable extinction ratio characteristics, and may also serve as an interface between a sequentially positioned polarization maintaining (PM) fiber, and a single mode (SM) fiber.

Abstract: The present invention is directed to an optical fiber grating having a core, that is capable of controlling the light signal transmission therethrough by causing at least one of: at least one spectral peak, and/or at least one spectral dip in its core light transmission spectrum, corresponding to at least one predetermined wavelength. The inventive optical fiber diffraction grating comprises at least one longitudinally positioned structural element of a predetermined geometric profile and that is configured for diffracting a portion of the transmitted light signal at at least one predefined wavelength thereof, from at least one core mode into at least one of: at least one cladding mode and/or at least one radiating mode. Various embodiments of a number of novel techniques for fabrication of the inventive optical fiber diffraction grating are provided, inclusive of a novel technique for fabricating the inventive grating from a single material.

Abstract: Advantageously, at least one embodiment of the present disclosure comprises a polarization maintaining PROFA (“PM-PROFA”) coupler in which the polarization axes of the individual vanishing core waveguides thereof are oriented or aligned without the need to adjust the orientation of each individual VC waveguide.