A plurality of bandpass filters (2) are arranged side by side in a row on a fixed surface (1a) of a glass block (1) and fixed using an adhesive (3). Each bandpass filter (2) includes a coating film (6) for transmitting or reflecting light depending on a wavelength. Each bandpass filter (2) includes a first surface (2a) fixed to the fixed surface (1a), and a second surface (2b) opposite to the first surface (2a) and having a width larger than that of the first surface (2a). Opposing side surfaces of the adjacent bandpass filters (2) include a first portion (2c) on the first surface (2a) side and a second portion (2d) on the second surface (2b) side. A spacing between the first portions (2c) of the adjacent bandpass filters (2) is wider than a spacing between the second portions (2d) of the adjacent bandpass filters (2).

An optical phased array comprises a first substrate layer, and a first device array on the first substrate layer. The first device array includes a first set of emitters and a first set of waveguides. Each waveguide in the first set of waveguides is respectively coupled to one of the emitters in the first set of emitters. A second substrate layer is over the first substrate layer in a stacked configuration, and a second device array is on the second substrate layer. The second device array includes a second set of emitters and a second set of waveguides. Each waveguide in the second set of waveguides is respectively coupled to one of the emitters in the second set of emitters. The second sets of emitters and waveguides are positioned on the second substrate to be offset with respect to the first sets of emitters and waveguides on the first substrate.

A pulse analysis system or method includes a frequency filter that receives an ultrafast pulse under test and disperses the pulse under test over a frequency range. The frequency filter separates the pulse under test into component frequency slices and provides the frequency slices to a detector coupled to a digitizer, which processes the digitized signal and collects a sonogram characteristic of the pulse under test. The frequency slices are arranged to overlap. Ptychography is performed on the sonogram to obtain characteristics of the pulse under test.

An optical circuit for routing a signal includes a coupler and first and second waveguides. The coupler has an input for the signal and has first and second outputs. The first waveguide has a first optical connection to the first output, and the second waveguide has a second optical connection to the second output. Both waveguides have the same propagation length. The first and second waveguides include different widths at the respective optical connections to the respective outputs. This coupler can be used with another input couplers, two additional waveguides, and two 2×2 output couplers to provide a 90-degree hybrid for mixing signal light and local oscillator light in a coherent receiver or the like.

An optical circuit for routing a signal includes a coupler and first and second waveguides. The coupler has an input for the signal and has first and second outputs. The first waveguide has a first optical connection to the first output, and the second waveguide has a second optical connection to the second output. Both waveguides have the same propagation length. The first and second waveguides include different widths at the respective optical connections to the respective outputs. This coupler can be used with another input couplers, two additional waveguides, and two 2×2 output couplers to provide a 90-degree hybrid for mixing signal light and local oscillator light in a coherent receiver or the like.

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 device includes an array of light emitters configured to generate multiple light beams to form an image, the image having a field of view and a planar waveguide having an edge configured to receive multiple light beams from the array of light emitters, each light beam associated with a portion of the field of view. The device also includes a lens array comprising multiple lenses linearly extended to overlap an edge portion of the planar waveguide, the lenses optically coupling the light beams into the planar waveguide, and one or more output couplers in the planar waveguide configured to direct the light beams into an eyebox, wherein the eyebox forms an area that includes a pupil of a viewer of the image.

A photonic integrated circuit platform includes a substrate, a first oxide layer disposed on the substrate and including an insulating transparent oxide, and a first optical element layer disposed on the first oxide layer and including a semiconductor material. The photonic integrated circuit platform further includes a second optical element layer disposed on the first optical element layer and including an insulating material different from the insulating transparent oxide of the first oxide layer, the second optical element layer further including a compound semiconductor material different from the semiconductor material of the first optical element layer, a second oxide layer disposed on the second optical element layer and including an insulating transparent oxide, and a plurality of optical elements formed by patterning the first optical element layer or the second optical element layer.

An optical signal generating apparatus is provided. A plurality of optical waveguides is disposed in different dielectric layers. A first light splitting pattern and a second light splitting pattern are disposed in the optical waveguides. The first light splitting pattern includes a first heterogeneous layer portion intersected with the second light splitting pattern in different dielectric layers to form at least one first intersection, the first heterogeneous layer portion and the second light splitting pattern are disposed in different optical waveguides, and a light beam with a specific wavelength, transmitted by the first light splitting pattern, is subject to a layer-to-layer transition before reaching the first intersection, so as to enter different optical waveguides.

A tunable element for an optical waveguide device, such as an Optical Phased Array (OPA), is described. Tunable element comprises three waveguide sections arranged such that light propagates through the first waveguide section, then through the second waveguide section and then through the third waveguide section, with light being either evanescently or directly coupled from one waveguide section to the next. The tunable element further comprises one or more resistive heating pad formed proximate to the second waveguide section. The first and third waveguide sections are formed from a first material and the second waveguide section is formed from a second, different material and the second material is more thermo-optically sensitive than the first material.