A multi-path interference filter. The multi-path interference filter includes a first port waveguide, a second port waveguide, and an optical structure connecting the first port waveguide and the second port waveguide. The optical structure has a first optical path from the first port waveguide to the second port waveguide, and a second optical path, different from the first optical path, from the first port waveguide to the second port waveguide. The first optical path has a portion, having a first length, within hydrogenated amorphous silicon. The second optical path has a portion, having a second length, within crystalline silicon, and the second optical path has either no portion within hydrogenated amorphous silicon, or a portion, having a third length, within hydrogenated amorphous silicon, the third length being less than the first length.

A dispersion-engineered 2D optical phased array device includes optical slow light waveguides [202, 208, 218] arranged parallel to each other; waveguide bends [206, 216] optically coupling ends of adjacent waveguides of the optical slow light waveguides to form a serpentine optical configuration; wherein the optical slow light waveguides comprise first waveguides of a first waveguide type and second waveguides of a second waveguide type, wherein the first waveguides and the second waveguides are arranged adjacent to each other and alternate with each other; wherein the optical slow light waveguides comprise phased array sections forming a phased array [214], wherein first waveguides and second waveguides have dispersion slopes of opposite sign and the same group index; wherein the optical slow light waveguides comprise slow light delay waveguide sections [210] that provide a delay between adjacent waveguides.

A thermal compensator, for use in connection with arrayed waveguide grating (AWG) modules which are, in turn, utilized in conjunction with wavelength multiplexing and de-multiplexing within optical networks, is disclosed. The thermal compensator comprises a bow-shaped frame member, a central bar member, and a screw. The bow-shaped frame member is characterized by a higher or great coefficient of thermal expansion (CTE) than that of the central bar member such that the bow-shaped frame member can expand and elongate at a greater rate than can the central bar member under hot temperature conditions, however, under cold temperature conditions, the rate of contraction of the bow-shaped member is effectively retarded by the slower rate of contraction of the central bar member. The bow-shaped frame member is adapted to be attached to a movable section of an athermal arrayed waveguide grating (AAWG) module such that the expansion and contraction movements of the bow-shaped member influence the movement of a movable section of the athermal arrayed waveguide grating (AAWG) module in order to maintain the proper focus of the athermal arrayed waveguide grating (AAWG) module across disparate temperature conditions within which the athermal arrayed waveguide grating (AAWG) module is designed to operate.

A photonic integrated circuit includes a slot optical waveguide having an optical core with sub-wavelength slot therein that is partially filled with a first lower-index material having a negative thermo-optic coefficient. The slot may also include a second lower-index material having a positive thermo-optic coefficient. The relative volume of the first lower-index material within the slot may be configured to provide athermal or nearly-athermal operation. Example applications include integrated AWG MUX/DEMUX devices, Mach-Zehnder modulators, and micro-ring resonators or modulators implemented with silicon-based or silicon-nitride based slot waveguides with reduced sensitivity to temperature changes.

An arrayed waveguide, an input-side slab waveguide, an output-side slab waveguide, an input waveguide, and an output waveguide are included. Provided are a groove formed to extend in a direction crossing a plurality of the output waveguides, and an optical conversion unit made of a conversion material that converts near-infrared light to visible light, the groove being filled with the optical conversion unit. The conversion material is, for example, a phosphor or fluorescent substance that converts near-infrared light to visible light.

An integrated wavelength division multiplexing (WDM) optical transceiver comprises the following elements: (1) a light source; (2) an array of photodiodes responsive to a plurality of optical signals and forming a plurality of electrical received information signals therefrom; and (3) a photonics integrated module (PIM) including transmission components and receiving components necessary to provide transceiver functionality. The transmission components include a demultiplexer, an electro-optic modulator array, and a multiplexer for combining a plurality of modulated optical signals onto a single output signal path as the transceiver output. The receiving components include a demultiplexer responsive to an incoming WDM signal for separating each wavelength component and creating a plurality of received optical signals.

An optical coupler device comprises a substrate having a substantially planar upper surface, and a grating structure on the upper surface of the substrate. In one embodiment, the grating structure comprises a copropagating array of waveguides that are substantially parallel to each other and extend along at least a portion of the upper surface of the substrate. Each of the waveguides has opposing sidewalls, wherein a width of each waveguide is defined by a distance between the opposing sidewalls. The opposing sidewalls each have a periodic structure that produces a sidewall modulation for each of the waveguides. An input port is in optical communication with the grating structure. The input port is configured to direct an input light beam in plane into the grating structure such that the beam propagates along the waveguides. The grating structure is configured to diffract the beam out of plane and into free space.

A super-compact arrayed waveguide grating (AWG) wavelength division multiplexer based on a sub-wavelength grating is provided and includes an input waveguide, a first planar waveguide, an arrayed waveguide, a second planar waveguide, and the output waveguide that are sequentially connected. The input waveguide has 1 port, and the output waveguide has 8 ports. The arrayed waveguide includes 50 equivalent uniform strip waveguides with the same length difference, and each of the equivalent uniform strip waveguides is configured as a sub-wavelength grating structure, thereby forming the effect of increasing group refractive index or transmission delay based on a slow light effect. The 8 channels with a channel spacing of 200 GHz have the minimum adjacent channel crosstalk of less than -27 dB, and the overall size is within 300×230 .Math.m.sup.2. In the multiplexer, the overall integration size of the device is reduced by an order of magnitude.

Provided is an optical wavelength multi/demultiplexing circuit with a high rectangular transmission loss spectrum that is able to secure loss flatness of a transmission band, maintain/reduce a guard bandwidth of wavelength channel spacing, and broaden a transmission bandwidth. The circuit uses a multimode waveguide for a connecting part between a field modulation device and an AWG. The field modulation device is constituted by a common input waveguide, an optical branching unit, optical delay lines, a multiplex interference unit, and a mode converter/multiplexer.

An athermal arrayed waveguide grating includes a silicon-based substrate and an athermal arrayed waveguide disposed on the silicon-based substrate. The athermal arrayed waveguide includes a cladding layer and a waveguide chip layer, the waveguide chip layer is disposed on the cladding layer and has a refractive index greater than that of the cladding layer; the waveguide core layer includes multilayer structures having a periodic configuration, the multilayer structure includes two layers of silica material and a negative temperature coefficient material disposed between the two layers of silica material; the negative temperature coefficient material is used to compensate for a dimensional deformation of the silicon-based substrate after being heated. The present invention simplifies the structure of the athermal arrayed waveguide grating, sets the negative temperature coefficient material in the waveguide core layer structure, and makes the final temperature coefficient of refractive index of the waveguide structure is a negative number.