A method for fiber-to-chip coupling is disclosed. The method comprises providing a photonic integrated circuit (PIC) that includes a substrate, a cladding layer on the substrate, and at least one waveguide embedded in the cladding layer, wherein the at least one waveguide has a waveguide interface. An optical fiber is positioned adjacent to the PIC, wherein the optical fiber has a fiber interface, and the fiber interface is aligned with the waveguide interface. A flowable inorganic oxide in liquid form is added to an area between the fiber interface and the waveguide interface. Thereafter, heat is applied to the area between the fiber interface and the waveguide interface for a period of time to cure the inorganic oxide, such that the optical fiber is coupled to the PIC. The cured inorganic oxide has a refractive index that substantially matches the refractive indices of the cladding layer and the optical fiber.

One example system comprises a plurality of substrates disposed in an overlapping arrangement. The plurality of substrates includes at least a first substrate and a second substrate. The system also comprises a first waveguide disposed on the first substrate to define a first optical path on the first substrate. The first waveguide is configured to guide light along the first optical path and to transmit, at an output section of the first waveguide, the light out of the first waveguide toward the second substrate. The system also comprises a second waveguide disposed on the second substrate to define a second optical path on the second substrate. An input section of the second waveguide is aligned with the output section of the first waveguide to receive the light transmitted by the first waveguide. The second waveguide is configured to guide the light along the second optical path.

A terahertz (THz) waveguide and method for production allows for THz waveguides to be used in or on a printed circuit board (PCB) such that the propagation of THz waves require less power, result in less signal loss due to radiation or dispersion, and propagate more efficiently. Additionally, the position and/or geometry of a waveguide, as well as any additional antenna or coupling element, may be adjusted on or in the PCB such that the electromagnetic field of the waveguide may more efficiently couple with the electromagnetic field of the PCB.

The optical fibers disclosed is a single mode optical fiber comprising a core region and a cladding region surrounding and directly adjacent to the core region. The core region can have a radius r.sub.1 in a range from 3 μm to 7 μm and a relative refractive index profile Δ.sub.1 having a maximum relative refractive index Δ.sub.1max in the range from 0.25% to 0.50%. The cladding region can include a first outer cladding region and a second outer cladding region surrounding and directly adjacent to the first outer cladding region. The first outer cladding region can have a radius r.sub.4a. The second outer cladding region can have a radius rob less than or equal to 45 μm and comprising silica based glass doped with titania.

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 optical waveguide structure has a waveguide core including an inner and an outer layer with different refractive indices, and a refractive index ratio of the different refractive indices is greater than or equal to 1.15. A dispersion controlling method using the optical waveguide structure includes: first, obtaining a dispersion curve having up to 5 zero-dispersion wavelengths by calculating based on a set of preset structural size parameters of the optical waveguide; and then, adjusting one or more of the width (W) of a contact surface between the inner layer and the substrate, the thickness (H) of a higher refractive index material, and the thickness (C) of a lower refractive index material, so as to implement dispersion control.

An interposer-type component carrier includes a stack comprising at least one electrically conductive layer structure and at least one electrically insulating layer structure; a cavity formed in an upper portion of the stack; an active component embedded in the cavity and having at least one terminal facing upwards; and a redistribution structure having only one electrically insulating layer structure above the component. A method of manufacturing an interposer-type component carrier is also disclosed.

According to an aspect of the present disclosure, an edge coupler for a photonic chip is provided. The edge coupler includes a substrate having a top surface, a sealed cavity in the substrate, a waveguide core, and a back-end-of-line stack. The sealed cavity has varying depths relative to the top surface of the substrate. The waveguide core is over the sealed cavity. The back-end-of-line stack includes a side edge, an interlayer dielectric layer, and an assisting waveguide. The assisting waveguide is on the interlayer dielectric layer adjacent to the side edge. The assisting waveguide and the waveguide core have an overlapping arrangement with the sealed cavity in the substrate.

An optical switch has latched switch states and includes optical fibers that are laterally joined together to define an optical switching portion. At least one phase change material (PCM) layer is on the optical switching portion so that a phase of the PCM layer determines a latched switch state from among the latched switch states.

A method includes: determining a first material and a second material of a photonic waveguide for propagating light, the photonic waveguide having a first section and a second section arranged in a first layer and a second layer, respectively, of the photonic waveguide; determining a spacing between the first layer and the second layer; determining a parameter set of a crosstalk reduction structure, according to the spacing, the first material and a wavelength of the light, to cause insertion losses of the first section and the second section to be lower than a predetermined threshold; and forming the first and second sections with the first and second materials, respectively, the first section having the crosstalk reduction structure overlapping the second section.