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.

An optical connector includes: a base substrate; an optical fiber on the base substrate; a plurality of optical devices having different wavelength bands and arranged in a curved shape concave toward the optical fiber to surround an end surface of the optical fiber; and an optical path changing device between the optical fiber and the plurality of optical devices and configured to diffract or refract incident light at different angles according to wavelength bands of the incident light. According to the optical connector, the arrangement of a plurality of light-emitting or light-receiving devices may be simplified and the number of communication channels may be easily increased in a multiplexing or demultiplexing structure in which a plurality of communication channels are provided using a single optical fiber.

A transmission grating includes: first light-transmissive regions having a refractive index of n.sub.1; and second light-transmissive regions having a refractive index of n.sub.2 that is smaller than n.sub.1. Light-reflecting interfaces on which light transmitted through the first light-transmissive regions is incident are in parallel with one another and are inclined such that a line normal to each of light-reflecting interfaces is at an inclination angle θ with respect to the flat light-incident surface and to the flat light-emitting surface, wherein 0°<θ<90°. When a thickness of the first light-transmissive regions in a direction perpendicular to the light-reflecting surfaces is t.sub.1 and a thickness of the second light-transmissive regions in a direction perpendicular to the light-reflecting surfaces is t.sub.2, the thickness t.sub.2, in μm, is in a range of 0.1/π(n.sub.1.sup.2−n.sub.2.sup.2).sup.1/2 to t.sub.1.

An optical cable includes a single optical connector configured for insertion into an optical receptacle so as to receive optical signals at a plurality of different wavelengths from the optical receptacle, and multiple electrical connectors, configured for insertion into respective electrical receptacles. Each electrical connector includes a transceiver configured to convert the optical signals into electrical output signals for output to an electrical receptacle. The optical cable further includes a plurality of optical fibers, having respective first ends connected together to the single optical connector so as to receive the optical signals. Each of the optical fibers has a respective second end coupled to a respective one of the electrical connectors. Wavelength selection optics are associated with the optical fibers so that the transceiver in each of the electrical connectors receives the optical signals at a different, respective one of the wavelengths.

Aspects of the present disclosure include methods, apparatuses, and computer readable media for transmitting a light such that it is incident on a multi-layer stack, wherein the multi-layer stack includes the feature and a region without the feature, detecting a narrow-band light from the feature and the region without the feature, wherein the feature has a first optical response in response to a wavelength of the narrow-band light and the region without the feature has a second optical response in response to the wavelength of the narrow-band light, and generating, based on the narrow-band light, an image indicative of where the first optical response and the second optical response occur on the multi-layer stack.

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.

The present disclosure relates to a signal processing apparatus and a signal processing method, a program, and a moving body that allow improvement of estimation accuracy for a self-position.

One of a plurality of wavelengths of light is selected, and the light with the selected wavelength is projected. Reflected light of the projected light is received that is reflected from a reflector corresponding to an object having a reflectance higher than a predetermined reflectance, and the reflector is detected. This prevents interference of light projected by another vehicle, enabling appropriate detection of the reflector and improvement of estimation accuracy for a self-position. The present disclosure is applicable to an in-vehicle system.

A light steeling system and method for diffractive steering of electromagnetic radiation such as visible light is disclosed. Embodiments of the light steering system include leaky-mode SAW modulators as light modulator devices. The SAW modulators preferably include reflective diffractive gratings. The gratings are mounted to/patterned upon an exit face that opposes an exit surface of the SAW modulator, in one example. Steering of light signals emitted from the SAW modulators in these systems can be accomplished by varying wavelength of light signals introduced to the SAW modulators, and/or by varying frequency of RF drive signals applied to the SAW modulators. In addition, light field generators that incorporate SAW modulators of the proposed light steering system within displays of the light field generators are also disclosed.

A variable wavelength filter includes: an input optical fiber; a diffraction grating that disperses input light from the input optical fiber; a variable mirror that has a reflective surface, wherein an angle of the reflective surface is adjustable, the variable mirror reflects the input light dispersed by the diffraction grating, the input light reflected by the variable mirror passes through a normal optical path, the input light that passes through the normal optical path has a wavelength band defined based on the angle of the reflective surface, and the defined wavelength band has a center wavelength corresponding to the angle of the reflective surface; an output optical fiber that outputs a portion of the input light that has passed through the normal optical path; and an optical detector disposed on a propagation path of the input light from the input optical fiber to the output optical fiber.

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.