An integrated photonic device for wavelength division multiplexing comprises: a wavelength-splitting/combining component configured to be re-used for both splitting a single signal to be split, wherein the signal to be split comprises plural wavelengths, to plural split signals, wherein each of the plural split signals is related to a unique wavelength band, and combining plural signals to be combined, wherein each of the plural signals to be combined is related to a unique wavelength band, to a single combined signal, wherein the wavelength-splitting/combining component comprises at least one output channel for providing an output signal and at least one response channel for receiving a response input signal from a light interaction induced by the output signal, wherein the output channel and the response channel are connected to different ports of the wavelength-splitting/combining component.

An integrated circuit comprises: at least one photonic layer that includes one or more optical waveguides; a first optical coupler that couples at least a first optical mode outside of the photonic layer to a first waveguide in the photonic layer; a photonic device that includes one or more ports in the photonic layer; a first multi-port optical coupler that includes three or more ports in the photonic layer, including a first port optically coupled to the first optical coupler, a second port optically coupled to a first port of the photonic device, and a third port optically coupled to a first optical reflector configured to send substantially all optical power emitted from the third port of the first multi-port optical coupler back to the third port of the first multi-port optical coupler.

A first waveguide and a second waveguide including a first layer and a second layer are provided. In a first longitudinal segment, the first layer gradually approaches a first waveguide in a first transverse direction. In a second longitudinal segment, the first and second waveguides are longitudinally oriented. In a third longitudinal segment, the first layer includes a length portion having a width in the first transverse direction that gradually decreases along the third longitudinal segment, and the second layer includes a length portion having a width in the first transverse direction that gradually increases along the third longitudinal segment.

A wavelength division multiplexing filter comprises: a first multi-order Mach-Zehnder interferometer comprising a plurality of first-order Mach-Zehnder interferometers, and a second multi-order Mach-Zehnder interferometer comprising a plurality of first-order Mach-Zehnder interferometers; wherein the first multi-order Mach-Zehnder interferometer and the second multi-order Mach-Zehnder interferometer are included in a group of multiple multi-order Mach-Zehnder interferometers arranged within a binary tree arrangement, the binary tree arrangement comprising: a first set of a plurality of multi-order Mach-Zehnder interferometers, the first set including the first multi-order Mach-Zehnder interferometer, and having an associated spectral response with a first spacing between adjacent passbands, and a second set of at least twice as many multi-order Mach-Zehnder interferometers as in the first set, the second set including the second multi-order Mach-Zehnder interferometer, and having an associated spectral response with a second spacing between adjacent passbands that is twice the first spacing.

An environmentally protected PIC, including an InP-based substrate having a first surface that is at least partially provided with an InP-based optical waveguide, and a dielectric protective layer arranged to cover at least the first surface of the InP-based substrate and the InP-based optical waveguide. The dielectric protective layer is configured to protect said PIC from environmental contaminants, to enable confinement of optical radiation in the dielectric protective layer in at least one direction that is transverse to a direction of propagation of the optical radiation, and to allow exchange of the optical radiation between the InP-based optical waveguide and the dielectric protective layer. An opto-electronic system including PIC.

Structures for a grating coupler and methods of fabricating a structure for a grating coupler. The structure includes a grating coupler having a central portion and edge portions. The central portion and the edge portions define a sidewall, and the central portion and the edge portions have a first longitudinal axis along which the edge portions are arranged in a spaced relationship. Each edge portion projects from the sidewall at an angle relative to the first longitudinal axis. A waveguide core is optically coupled to the grating coupler. The first longitudinal axis is aligned in a first direction, and the waveguide core has a second longitudinal axis that is aligned in a second direction different from the first direction.

An optical transmission system includes a transmitting node that transmits wavelength light of an operational path to an optical waveguide, and a receiving node that receives the wavelength light from the optical waveguide. The transmitting node includes a light source that generates spontaneously emitted light and a wavelength selector that generates and outputs dummy wavelength light from the spontaneously emitted light generated by the light source. The receiving node includes an extractor that extracts spectral data of the dummy wavelength light passed in the optical waveguide. The optical transmission system further includes an obtainer that obtains a band state of the operational path from the spectral data of the dummy wavelength light extracted by the extractor.

An illuminator for a display panel includes a light source for providing a light beam and a lightguide coupled to the light source for receiving and propagating the light beam along the substrate. The lightguide includes an array of out-coupling gratings that runs parallel to the array of pixels for out-coupling portions of the light beam from the lightguide such that the out-coupled light beam portions propagate through the substrate and produce an array of optical power density peaks at the array of pixels due to Talbot effect. A period of the array of peaks is an integer multiple of a pitch of the array of pixels.

A chamberless smoke detector includes a source laser, a grating coupler, a transmitting optical phase array, a receiving optical phase array, and a processing unit.

A wavelength demultiplexer includes a photonic circuit and a control circuit that adjusts wavelength characteristics of the photonic circuit. The photonic circuit converts two orthogonal polarized waves contained in the incident light into two same polarized waves, which are supplied to a first optical demultiplexing circuit and a second optical demultiplexing circuit provided in the photonic circuit and having the same configuration. The photonic circuit supplies a total output power of monitor lights extracted from the same positions in the first optical demultiplexing circuit and the second optical demultiplexing circuit to the control circuit. The control circuit controls a first wavelength characteristic of the first optical demultiplexing circuit and a second wavelength characteristic of the second optical demultiplexing circuit based on the total output power of the monitor lights.