A photonic integrated circuit is presented that includes a substrate, and a first and second waveguide patterned on the substrate. The first waveguide guides an input beam of radiation. The photonic integrated circuit also includes a coupling region, wherein the first and second waveguides each pass through the coupling region. One or more modulating elements are coupled to each of the first and second waveguides. The first waveguide and the second waveguide have a first facet and a second facet, respectively, and first and second reflections are generated at the first and second facets within the first and second waveguides, respectively. The one or more modulating elements coupled to each of the first and second waveguides are designed to adjust the phase of the first and second reflections before the first and second reflections pass through the coupling region.

A modified directional coupler structure is used to provide a controllable time delay or phase shift for radiation propagating through the structure. A longitudinal displacement of the interaction region of the directional coupler relative to one or both of the waveguides of the directional coupler provides this effect. Double flexure arrangements can be used to provide longitudinal displacement with substantially no corresponding lateral displacement (or vice versa). In some embodiments, lateral and longitudinal displacement of the waveguides of the directional coupler are independently adjustable to provide full control of the power splitting and phase shift/time delay of the directional coupler.

Evanescently-coupled planar waveguides for enhancing total internal reflection fluorescence microscopy are disclosed. The waveguides include multiple thin layers of one or more materials on a cover slip arranged resonantly enhance the optical field at the surface of the layer stack by evanescently coupling to a leaky guided mode.

The present invention discloses a mode multiplexer/demultiplexer and a switching node. The mode multiplexer/demultiplexer includes a multi-mode optical waveguide, a first transmission optical waveguide, and a second transmission optical waveguide. The multi-mode optical waveguide includes a first mode channel and a second mode channel. The first transmission optical waveguide includes a first coupling region that includes a first fundamental-mode channel, and the first fundamental-mode channel performs optical mode coupling with the first mode channel in the multi-mode optical waveguide. The second transmission optical waveguide includes a second coupling region that includes a second fundamental-mode channel, and the second fundamental-mode channel performs optical mode coupling with the second mode channel in the multi-mode optical waveguide. An effective refractive index of a fundamental-mode optical signal in the first coupling region is different from an effective refractive index of the same fundamental-mode optical signal in the second coupling region.

An assembly including a first waveguide produced in a first photonic chip and that extends in a first direction in order to guide an optical signal at a wavelength λ, an array of a plurality of second waveguides, which is produced in a second photonic chip adjoined to the first photonic chip, and a power summer including inputs that are optically connected to one end of each of the second waveguides. Each of the second waveguides includes upstream and downstream segments that are offset with respect to each other in the second direction. The configurations of the first waveguide and of the second waveguides are such that, for any position of the first waveguide above the array, the distance between one of the segments of the first waveguide and one of the segments of one of the second waveguides is smaller than λ/2.

A method for producing a semiconductor optical device includes the steps of bonding a semiconductor chip to an SOI substrate having a waveguide, the semiconductor chip having an optical gain and including a first cladding layer, a core layer, and a second cladding layer that contain III-V group compound semiconductors and are sequentially stacked in this order, forming a covered portion with a first insulating layer on the second cladding layer, etching partway in the thickness direction the second cladding layer exposed from the first insulating film, forming a second insulating film covering from the covered portion to a part of a remaining portion of the second cladding layer, and forming a first tapered portion that is disposed on the waveguide and tapered along the extending direction of the waveguide by etching the core layer and the second cladding layer exposed from the second insulating film.

A compact collimator or projector includes a waveguide having a slab core structure supporting at least two lateral modes of propagation. A light beam coupled into a first mode propagates to an edge of the waveguide where it is reflected by a reflector to propagate back. Upon propagation back and forth, the light is converted into a second mode. An out-coupling region, such as an evanescent coupler, is provided to out-couple the light propagating in the second mode. The reflector may have focusing power to collimate the out-coupled light beam. The light beam may be converted from the first to the second mode without being reflected from a reflector.

An optical phase shifter may include a waveguide core that has a top surface, and a semiconductor contact that is laterally displaced relative to the waveguide core and is electrically connected to the waveguide core. A top surface of the semiconductor contact is above the top surface of the waveguide core. The waveguide core may include a p-type core region and an n-type core region. A p-type semiconductor region may be in physical contact with the n-type core region of the waveguide core, and an n-type semiconductor region may be in physical contact with the p-type core region of the waveguide core. A phase shifter region and a light-emitting region may be disposed at different depth levels, and the light-emitting region may emit light from a phase shifter region that is in a position adjacent to the light-emitting region.

An optical phase shifter may include a waveguide core that has a top surface, and a semiconductor contact that is laterally displaced relative to the waveguide core and is electrically connected to the waveguide core. A top surface of the semiconductor contact is above the top surface of the waveguide core. The waveguide core may include a p-type core region and an n-type core region. A p-type semiconductor region may be in physical contact with the n-type core region of the waveguide core, and an n-type semiconductor region may be in physical contact with the p-type core region of the waveguide core. A phase shifter region and a light-emitting region may be disposed at different depth levels, and the light-emitting region may emit light from a phase shifter region that is in a position adjacent to the light-emitting region.

The present disclosure relates to semiconductor structures and, more particularly, to waveguide attenuators and methods of manufacture. The structure includes: a main bus waveguide structure; a first hybrid waveguide structure evanescently coupled to the main bus waveguide structure and comprising a first geometry of material; and a second hybrid waveguide structure evanescently coupled to the main bus waveguide structure and comprising a second geometry of the material.