An optical module capable of suppressing deterioration of an adhesive layer and having a resistance to high-power light even when high-energy light propagates is configured by connecting an optical fiber to a PLC. The optical fiber is provided with an etching face at a recessed area where a cladding region on its side face is partially removed over a length L in a light propagation direction from an input/output end connected to the PLC, and the PLC is also provided with an etching face at a recessed area where a cladding layer is partially removed over the length L in the light propagation direction from an input/output end connected to the optical fiber. The adhesive layer made of a UV cured resin is interposed between the etching faces to bond and fix the etching faces to each other, and a core of the optical fiber and a core layer of the PLC form a directional coupler for linearly dispersing energy density.

A photonic integrated circuit (PIC) includes one or more couplers to interface a light source with the PIC, a splitter directly coupled to the one or more couplers at a coupling point of the PIC, a modulator to receive light from the couplers, and a connecting waveguide to connect the splitter to the modulator. The waveguide may be a rib waveguide. The PIC may be integrated with devices such as a CWDM or a PSM device, and may provide improved performance and lower attention for high optical power applications.

In integrated optical structures (e.g., silicon-to-silicon-nitride mode converters) implemented in semiconductor-on-insulator substrates, wire waveguides whose sidewalls substantially consist of portions coinciding with crystallographic planes and do not extend laterally beyond the top surface of the wire waveguide may provide benefits in performance and/or manufacturing needs. Such wire waveguides may be manufactured, e.g., using a dry-etch of the semiconductor device layer down to the insulator layer to form a wire waveguide with exposed sidewalls, followed by a smoothing crystallographic wet etch.

A thermo-optic phase shifter comprises an optical waveguide comprising a P-type region comprising a first contact, an N-type region comprising a second contact, and a waveguide region disposed between the P-type region and the N-type region and having a raised portion. The thermo-optic phase shifter further comprises one or more heating elements. The one or more heating elements include one or more discrete resistive heating elements or the P-type and N-type regions driven as resistive heating elements.

Structures for a polarization rotator and methods of fabricating a structure for a polarization rotator. The structure includes a substrate, a first waveguide core over the substrate, and a second waveguide core over the substrate. The second waveguide core is positioned proximate to the section of the first waveguide core. The second waveguide core is comprised of a material having a refractive index that is reversibly variable in response to a stimulus.

In an integrated optical device, squeezed light is used internally to effectively increase an optical modulation effect. One exemplary device operates by squeezing the light at the input, then sending it through an electro-optic stage where its phase picks up the signal of interest, and finally anti-squeezing it to obtain a displaced coherent state. Thus the displacement is amplified by the level of squeezing that is achieved inside the device and it is thereby less sensitive to loss. Since this device behaves simply as an electro-optic modulator, albeit one with an exponentially enhanced sensitivity, no extra considerations are needed to integrate the modulator into a system. Such devices can be operated as modulators or as sensors, and can make use of optical phase shift effects other than the electro-optic effect.

An apparatus includes a lithium niobate (LN) layer, and a planar electro-optical modulator having at least one hybrid optical core segment formed of a portion of the LN layer and an optical guiding rib. The optical guiding rib may be located in a top silicon layer of a silicon photonics (SiP) chip, to which a thin-film LN chip is flip-chip mounted, and may be coupled to optical waveguide cores in a first silicon core layer of the SiP chip. One or more drive electrodes are disposed between a substrate of the SiP chip and the LN layer. In some embodiments hybrid optical core segments may include silicon nitride core segments and may form an MZM configured to be differentially or dual-differentially driven.

A waveguide element includes a first waveguide and a second waveguide. The first waveguide includes a first main rib and a first slab that has a smaller thickness than that of the first main rib and in which a slab mode of light propagates. The second waveguide includes a second main rib that is optically coupled with the first main rib and in which the light propagates, a second slab that has a smaller thickness than that of the second main rib, that is optically coupled with the first slab, and in which the slab mode propagates, and a side rib that has a larger thickness than that of the second slab. The slab mode that propagates through the second slab transitions to the side rib in accordance with travel of the light that propagates in the first main rib and the second main rib.

An optical out-coupler unit for out-coupling light from a waveguide, comprising a substrate having a planar top surface, a waveguide arranged on the top surface of the substrate and having a facet, a reflective surface, wherein the reflective surface is arranged spaced apart from the facet and opposing the facet, wherein the reflective surface is inclined with respect to a normal to the top surface of the substrate by more than 45°. The optical out-coupler may be part of a photonic integrated chip (PIC).

Provided are three dimensional, stretchable, optical sensor networks that can localize deformations. The devices described herein are suitable for uses in soft robots to determine the position of external contact, such as touching, and possibly internal deformations that may be caused by actuation. Sensor networks of the present disclosure contain a substrate, such as a 3D lattice, and cores having a cladding, such as air. Light passes through the cores and upon deformation of the substrate, cores may come into contact, allowing light to couple between cores due to frustrated total internal reflection. The resulting changes in intensity in the cores can be used to determine the placement and magnitude of deformation.