An optical device has a first photonic waveguide provided on a substrate, a second photonic waveguide provided on the substrate and extending side by side with the first photonic waveguide, and a looped waveguide continuously connecting the first photonic waveguide and the second photonic waveguide on the substrate, wherein a width of at least one of the first photonic waveguide or the second photonic waveguide varies continuously along an optical axis, between a first position located at a side opposite to the looped waveguide and a second position connected to the looped waveguide, and wherein cross sections of the first photonic waveguide and the second photonic waveguide are congruent at the second position, and are incongruent at the first position.

Techniques and mechanisms for optically coupling a photonic integrated circuit (PIC) chip to an optical fiber via a planar optical waveguide structure. In an embodiment, a PIC chip comprises integrated circuitry, photonic waveguides, and integrated edge-oriented couplers (IECs) which are coupled to the integrated circuitry via the photonic waveguides. The PIC chip forms respective divergent lens surfaces of the IECs, which are each at a respective terminus of a corresponding one of the photonic waveguides. A planar optical waveguide structure, which is adjacent to the IECs, comprises a core which is optically coupled between the PIC chip and an array of optical fibers. In another embodiment, an edge of the PIC forms a stepped structure, wherein an upper portion of the stepped structure comprises the plurality of coplanar IECs, and a lower portion of the stepped structure extends past the plurality of coplanar IECs.

Disclosed are methods of providing a hermetically sealed optical connection between an optical fiber and an optical element of a chip and a photonic-integrated chip manufactured using such methods.

Structures for an edge coupler and methods of fabricating a structure for an edge coupler. A waveguide core includes a waveguide core section that has a first notched sidewall, a second notched sidewall, and an end surface connecting the first notched sidewall to the second notched sidewall. Segments are positioned with a spaced arrangement adjacent to the end surface of the waveguide core section, and a slab layer is adjoined to the segments, the first notched sidewall of the waveguide core section, the second notched sidewall of the waveguide core section, and the end surface of the waveguide core section. The segments and the waveguide core section have a first thickness, and the slab layer has a second thickness that is less than the first thickness.

Structures for an edge coupler and methods of fabricating a structure for an edge coupler. A first waveguide core has a first section that has a tapered shape and a second section that is adjoined to the first section. Multiple segments are positioned with a spaced arrangement adjacent to an end surface of the second section of the first waveguide core. A slab layer is adjoined to the first section of the first waveguide core. A second waveguide core has a section that overlaps with the first section of the first waveguide core to define a layer stack. The section of the second waveguide core has a tapered shape, and the first and second waveguide cores are comprised of different materials. The first section of the first waveguide core has a first thickness, and the slab layer has a second thickness that is less than the first thickness.

A process for delaying a useful optical signal (P1) having a wavelength value λ between 0.2 μm and 3 μm, with respect to a reference optical signal (P2) having the same wavelength value λ. The process includes having the useful optical signal propagate along a tapered fiber portion. A length of the tapered fiber portion can be varied using stretching means that are light, less cumbersome and less expensive compared to those necessary for a standard optical fiber. In addition, the delay value which is effective for the useful optical signal can be varied over a wide range. Such process can be useful for interferometry measurements in particular.

An integrated optical component, including a transparent pad arranged on the upper face of the basic optical component, the transparent pad including a plane mirror at its upper face, and the basic optical component including a convergent mirror at its upper face, the plane and convergent mirrors being arranged such that the light beam is propagated between the internal light gate and the external light gate by passing through the transparent pad by reflection on the plane mirror and by reflection on the convergent mirror.

Methods of fabricating optical devices with high refractive index materials are disclosed. The method includes forming a first oxide layer on a substrate and forming a patterned template layer with first and second trenches on the first oxide layer. A material of the patterned template layer has a first refractive index. The method further includes forming a first portion of a waveguide and a first portion of an optical coupler within the first and second trenches, respectively, forming a second portion of the waveguide and a second portion of the optical coupler on a top surface of the patterned template layer, and depositing a cladding layer on the second portions of the waveguide and optical coupler. The waveguide and the optical coupler include materials with a second refractive index that is greater than the first refractive index.

Provided here are: a semiconductor laser section formed on a surface of a semiconductor substrate; a spot-size converter section in which an optical waveguide having a core layer for propagating laser light emitted from the semiconductor laser section is provided; and a monitor PD section which is provided on the spot-size converter section laterally with respect to a propagation direction of the laser light; wherein, the regions of a PD anode electrode and a PD cathode electrode in the monitor PD section are partially opposed to each other through an insulating film, so that the surge breakdown voltage of the monitor PD section is increased.

A semiconductor device is provided. The semiconductor device includes a waveguide over a substrate. The semiconductor device includes a first dielectric structure over the substrate, wherein a portion of the waveguide is in the first dielectric structure. The semiconductor device includes a second dielectric structure under the waveguide, wherein a first sidewall of the second dielectric structure is adjacent a first sidewall of the substrate.