Optical coupling techniques between an optical fiber and another optical device, such as a planar optical waveguide, or a probed region are disclosed. An optical fiber for lateral optical coupling includes a cladding, a core disposed in the cladding, a reflecting structure inclined relative to the fiber axis, and a light-converging structure embedded in the cladding. The reflecting structure is configured to reflect light between the core and a lateral coupling path extending and providing lateral optical coupling between the core and an exterior of the fiber. The cladding-embedded light-converging structure is configured to intercept and converge light traveling along the lateral coupling path. In some implementations, the optical fiber is a fiber-optic transition coupled between a main optical fiber and another optical device or a probed region. A coupled optical system including an optical fiber coupled to another optical device is also disclosed.

A ferrule structure includes: a ferrule body including a guide hole that accepts insertion of a guide pin, and a fiber hole that accepts insertion of an optical fiber and that is disposed in an opening surface of the ferrule body; and a lens plate including a guide hole that accepts insertion of the guide pin, a lens part, and an abutment surface that abuts an endface of the optical fiber. A recess is disposed in at least one of the ferrule body and the lens plate. A matching material filling gap, that is to be filled with a refractive index matching material, is formed with the recess, between the opening surface of the ferrule body and the abutment surface of the lens plate.

An optical coupler including a first surface intended to receive a light beam and a second surface intended to supply at least part of the light beam, and a lateral wall connecting the first surface to the second surface, the lateral wall successively including, between the first and second surfaces, a first concave portion and a first convex portion.

A fiber optic ferrule has a main body with a top surface and a bottom surface and extends between a front end and a back end. The front face includes a recessed portion with a plurality of optical lenses. The front face is configured to allow for the plurality of lenses to be on an angle relative to the front face and the fiber optic ferrule will have not any undercuts and allow the fiber optic ferrule to be ejected from a mold without engaging any portions of the mold.

Optical coupling techniques between an optical fiber and another optical device, such as a planar optical waveguide, or a probed region are disclosed. An optical fiber for lateral optical coupling includes a cladding, a core disposed in the cladding, a reflecting structure inclined relative to the fiber axis, and a light-converging structure embedded in the cladding. The reflecting structure is configured to reflect light between the core and a lateral coupling path extending and providing lateral optical coupling between the core and an exterior of the fiber. The cladding-embedded light-converging structure is configured to intercept and converge light traveling along the lateral coupling path. In some implementations, the optical fiber is a fiber-optic transition coupled between a main optical fiber and another optical device or a probed region. A coupled optical system including an optical fiber coupled to another optical device is also disclosed.

Disclosed are a collimator for reducing noise of a scanned image and an imaging catheter system comprising the same. The disclosed noise attenuation collimator comprises: a transparent tube having a diameter larger than a cladding diameter of double-clad fiber, wherein a coatingless region of the double-clad fiber is inserted into the transparent tube; and a first resin layer which is applied to an exterior of the transparent tube and has a refractive index lower than the refractive index of the transparent tube.

A laser hazard at the time of non-connection can be prevented with a simple structure. A cylindrical connector exterior, and a block that is incorporated in one end side of the connector exterior and in which a light emitting portion or a light incident portion is mounted toward another end side are included. The light emitting portion or the light incident portion is mounted on the block such that an optical axis direction of the light emitting portion or the light incident portion is inclined with respect to a longitudinal direction of the connector exterior. For example, the connector exterior has a length at which at least a part of light emitted from the light emitting portion can be emitted to an inner side (inner wall) of the connector exterior.

Methods and systems for optical interconnection.

A wavelength-division multiplexing (WDM) optical assembly with multiple collimator sets is disclosed herein. The WDM optical assembly includes a WDM optical core subassembly including at least one optical signal router, at least one WDM filter, and a first and second WDM collimator sets. The first WDM collimator set includes a first common optical collimator and at least two channel collimators and the second WDM collimator set includes a second common optical collimator and at least two channel collimators. At least a portion of the first WDM collimator set is optically positioned on a first surface of at least one substrate, and at least a portion of the second WDM collimator set is optically positioned on a second surface of the at least one substrate opposite the first surface. The WDM optical core subassembly increases lane density while decreasing size and minimizing complexity by using a plurality of WDM common ports.

An optical fiber connection structure includes: a tubular member; a first collimator attached to a first end of the tubular member in an axial direction; and a second collimator attached to a second end of the tubular member. The first collimator includes a first optical fiber, a first ferrule, a first lens, and a first sleeve. The second collimator includes a second optical fiber, a second ferrule terminating the second optical fiber, a second lens, and a second sleeve. The first sleeve is fixed to the first end via adhesive in a state where the first lens faces the tubular member, and the second sleeve is fixed to the second end via adhesive in a state where the second lens faces the tubular member. An outer diameter of the second ferrule is larger than that of the second lens.