A photonic integrated circuit chip includes vertical grating couplers defined in a first layer. Second insulating layers overlie the vertical grating coupler and an interconnection structure with metal levels is embedded in the second insulating layers. A cavity extends in depth through the second insulating layers all the way to an intermediate level between the couplers and the metal level closest to the couplers. The cavity has lateral dimensions such that the cavity is capable of receiving a block for holding an array of optical fibers intended to be optically coupled to the couplers.

An apparatus including a photonic integrated circuit (PIC) coupled to an optical bench is disclosed. The PIC includes at least one grating coupler disposed thereon and the optical bench includes an optical system disposed thereon. The apparatus also includes an integrated heater at an upper surface of the PIC under the optical bench or at a bottom surface of the optical bench over the PIC. The apparatus also includes a layer of solder disposed between the PIC and the optical bench for coupling the bottom surface of the optical bench to the PIC. In some implementations, the layer of solder is in thermal communication with the integrated heater.

A master oscillator power amplifier comprises a semiconductor laser formed on a substrate and configured to output an optical signal, and a semiconductor optical amplifier (SOA) formed on the substrate. The SOA comprises an optical waveguide having an optically active region, wherein the optical waveguide is configured to expand a mode size of the optical signal along at least two dimensions.

An optical density measuring apparatus and an optical waveguide capable of increasing the degree of design freedom are provided. The optical density measuring apparatus is for measuring density of a gas or a liquid to be measured and includes a light source capable of irradiating light into a core layer, a detector capable of receiving light propagated through the core layer, and an optical waveguide. The optical waveguide includes a substrate and the core layer, which includes a diffraction grating unit and a light propagation unit capable of propagating light in an extending direction of the light propagation unit. The diffraction grating unit and a portion of the core layer are separated in the thickness direction of the optical waveguide.

An optical density measuring apparatus for measuring density of a gas or a liquid to be measured includes a light source capable of irradiating light into a core layer, a detector capable of receiving light propagated through the core layer, and an optical waveguide that includes a substrate and the core layer. The core layer includes a light propagation unit and a first diffraction grating unit that receives light from the light source and guides the light to the light propagation unit, which includes a propagation channel capable of propagating light in an extending direction of the light propagation unit. The first diffraction grating unit is disposed near to and facing a light-emitting surface of the light source. The first diffraction grating unit includes first diffraction gratings, at least two of which receive light emitted from the same light-emitting surface of the light source.

An optomechanical system including a guide structure, to guide a light beam; and two waveguide segments. Each guide structure include beams that together form two combs partially nested one in the other. At least one beam is free to move in translation along an axis orthogonal to the long axis of the guide structure. A displacement into an optical phase shift, while limiting additional effects on the intensity.

Structures for a grating that may be deployed in edge coupler and methods of forming such structures. The structure comprises a waveguide core positioned on a substrate. The waveguide core includes a longitudinal axis and a grating having first and second segments positioned along the longitudinal axis in a spaced-apart arrangement. The first segment has a first sidewall sloped at a first angle relative to the longitudinal axis and a second sidewall oriented transverse to the longitudinal axis. The second segment has a first sidewall sloped at a second angle relative to the longitudinal axis and a second sidewall oriented transverse to the longitudinal axis. The first sidewall of the first segment positioned adjacent to the first sidewall of the second segment.

Structures for a grating that may be deployed in edge coupler and methods of forming such structures. The structure comprises a waveguide core positioned on a substrate. The waveguide core includes a longitudinal axis and a grating having first and second segments positioned along the longitudinal axis in a spaced-apart arrangement. The first segment has a first sidewall sloped at a first angle relative to the longitudinal axis and a second sidewall oriented transverse to the longitudinal axis. The second segment has a first sidewall sloped at a second angle relative to the longitudinal axis and a second sidewall oriented transverse to the longitudinal axis. The first sidewall of the first segment positioned adjacent to the first sidewall of the second segment.

Disclosed is a laser device. The laser device includes a substrate, a pump light source which is disposed on the substrate and provided with a light emitting layer configured to generate pump light, and an upper waveguide which is disposed above the pump light source in a first direction and provided with an upper resonator configured to allow laser light to be generated and resonate by using the pump light.

A photonic calorimeter converts ionizing radiation dose to heat and includes: a radiation absorber, a temperature compensator disposed within the radiation absorber, a compensation waveguide, a compensation resonator, a compensation resonator, a thermal isolator on which the radiation absorber is disposed and that thermally isolates the radiation absorber from heat loss by thermal transfer due to physical contact by an object, and the temperature compensator changes the optical resonance of the compensation resonator in response to a change in temperature of the radiation absorber due to absorption of the ionizing radiation by the radiation absorber.