A disclosed multimode optical fiber comprises a core and a cladding surrounding the core. The core has an outer radius r.sub.1 in between 20 μm and 30 μm. The cladding includes a first outer cladding region having an outer radius r.sub.4a and a second outer cladding region having an outer radius r.sub.4b less than or equal to 45 μm. The second outer cladding region comprises silica-based glass doped with titania. The optical fiber further includes a primary coating with an outer radius r.sub.5 less than or equal to 80 μm, and a thickness (r.sub.5−r.sub.4) less than or equal to 30 μm. The optical fiber further includes a secondary coating with an outer radius r.sub.6 less than or equal to 100 μm. The secondary coating has a thickness (r.sub.6−r.sub.5) less than or equal to 30 μm, and a normalized puncture load greater than 3.6×10.sup.−3 g/micron.sup.2.

An implantable optical sensor (1) comprising a substrate (2) and at least one optical microstructure (3) for evanescent field sensing integrated with the substrate (2), the at least one optical microstructure (3) being positioned to form an optical interaction area (4) on a part of a surface (5) of the substrate (2), the optical assembly (1) further comprising a thin protective layer (6) covering at least the optical interaction area (4), the thin protective layer (6) being in a predetermined material with corrosion-protection characteristics and having a predetermined thickness, so as not to affect the evanescent field sensing.

A photonic integrated circuit device can comprise one or more layers having different refraction indices that cause optical coupling issues and losses from layer variations. A film of material can be applied to a layer of the photonic integrated circuit to avoid the issues to increase the optical bandwidth of the photonic integrated circuit device and decrease sensitivity to manufacturing and design processes.

A wavelength checker includes an optical waveguide chip. A known arrayed-waveguide diffraction grating is formed on the optical waveguide chip. The wavelength checker includes a light conversion unit made of a conversion material that converts infrared light into visible light. The light conversion unit is arranged on an output side of a plurality of first output waveguides of the optical waveguide chip to be capable of receiving light emitted from the plurality of first output waveguides. The light conversion unit is formed on a side surface of a support facing an output end surface of the optical waveguide chip. The support is fixed to a main board.

A process for forming glass planar waveguide structure includes producing or obtaining a fusion drawn glass laminate (10) comprising a core glass layer (10) and a first clad glass layer (14) and a second clad glass layer (16) then removing or thinning portions of at least the second glass clad layer (16) leaving remaining or thicker portions of the second glass clad layer (16), the remaining or thicker portions corresponding to a planar waveguide pattern and resulting in a glass planar waveguide structure.

An optical fiber array includes a V-groove substrate in which a V-groove for optical fiber alignment is formed, a pressing plate laminated and bonded on the V-groove substrate, and an optical fiber bonded and fixed in the V-groove of the V-groove substrate, wherein a distance between the optical fiber and the V-groove is less than 20 μm.

A manufacturing method of an optical waveguide device that allows light to propagate through a core formed within a cladding formed on a substrate, the core having a higher refractive index than the cladding, includes: layering a first cladding-material layer for the cladding and a core-material layer for the core sequentially on the substrate; forming the layered core-material layer into the core having a waveguide shape, and removing a first part of the core, the first part being positioned at a portion where a slit is to be formed, to thereby form a gap in the core; layering a second cladding-material layer for the cladding to cover the first cladding-material layer and the core; and removing, by dry-etching, a second part of the first and second cladding-material layers, the second part being positioned at the portion where the slit is to be formed, to thereby form the slit.

A photonic integrated circuit (PIC) for determining a wavelength of an input signal is disclosed. The PIC comprises: a substrate; a first Mach-Zehnder Interferometer (MZI) disposed over the substrate, comprising first optical waveguides having a first optical path length difference, and configured to receive a first output optical signal from a light source. The PIC also comprises a second Mach-Zehnder Interferometer (MZI) disposed over the substrate, comprising second optical waveguides having a second optical path length difference, which is greater than the first optical path length difference, and configured to receive a second output optical signal from the light source.

A photonic integrated circuit (PIC) package comprising a first die, the first die comprising a first optical waveguide and a first trench extending from a first edge of the first die to the first optical waveguide. The first trench is aligned with the first optical waveguide. A second die comprises a second optical waveguide and a second trench extending from a second edge of the second die to the second optical waveguide. The second trench is aligned with the second optical waveguide. An optical wire comprising an uncladded glass fiber comprises a first terminal portion extending within the first trench and a second terminal portion extending within the second trench. The first terminal portion is aligned with the first optical waveguide and the second terminal portion is aligned with the second optical waveguide.

Embodiments disclosed herein include electronic packages with a core that includes an optical waveguide and methods of forming such electronic packages. In an embodiment, a package substrate comprises a core, and a photonics die embedded in the core. In an embodiment, the electronic package further comprises an optical waveguide embedded in the core. In an embodiment, the optical waveguide optically couples the photonics die to an edge of the core.