A wavelength division multiplexer is disclosed. The wavelength division multiplexer may include an input waveguide, in which a plurality of Bragg gratings for separating multiplexed optical signals into respective optical signals are provided, and a plurality of output waveguides connected to the input waveguide and configured to receive the optical signals separated by the plurality of Bragg gratings. The plurality of Bragg gratings may include a first Bragg grating including first protrusions each having a first width, and a second Bragg grating including second protrusions each having a second width larger than the first width. Each of the first and second protrusions may include a curved side surface, to which a corresponding one of the optical signals is incident.

The optical device coupleable to a waveguide to receive an optical signal from the waveguide generally has at least two diffraction grating devices optically coupled to one another and having corresponding spectral responses, the spectral response of at least one of said diffraction grating devices being tunable to adjust an amount of overlapping between the spectral responses of the at least two diffraction grating devices.

Provided are a Bragg grating and a spectroscopy device including the same. The Bragg grating is disposed at each of opposite ends of a resonator for reflecting light of a certain wavelength band and includes a core member extending from a waveguide of the resonator in a lengthwise direction of the waveguide; a plurality of first refractive members protruding from the core member and spaced apart from each other along the lengthwise direction; and a second refractive member filling spaces between the first refractive members and having a refractive index different from a refractive index of the first refractive members.

Systems and method for the delivery of a pump laser using optical diffraction are described herein. In certain embodiments, a system includes a substrate and a waveguide layer formed on the substrate. The waveguide layer includes a first waveguide of a first material configured to receive a probe laser for propagating within the first waveguide. The waveguide layer additionally includes a second waveguide configured to receive a pump laser for propagating within the second waveguide. Further, the waveguide layer includes one or more diffractors configured to direct a portion of the pump laser out of the second waveguide and through the first waveguide.

An eyepiece for a head-mounted display includes one or more first waveguides arranged to receive light from a spatial light modulator at a first edge, guide at least some of the received light to a second edge opposite the first edge, and extract at least some of the light through a face of the one or more first waveguides between the first and second edges. The eyepiece also includes a second waveguide positioned to receive light exiting the one or more first waveguides at the second edge and guide the received light to one or more light absorbers.

Provided are a Bragg grating and a spectroscopy device including the same. The Bragg grating is disposed at each of opposite ends of a resonator for reflecting light of a certain wavelength band and includes a core member extending from a waveguide of the resonator in a lengthwise direction of the waveguide; a plurality of first refractive members protruding from the core member and spaced apart from each other along the lengthwise direction; and a second refractive member filling spaces between the first refractive members and having a refractive index different from a refractive index of the first refractive members.

A wavelength division multiplexer is disclosed. The wavelength division multiplexer may include an input waveguide, in which a plurality of Bragg gratings for separating multiplexed optical signals into respective optical signals are provided, and a plurality of output waveguides connected to the input waveguide and configured to receive the optical signals separated by the plurality of Bragg gratings. The plurality of Bragg gratings may include a first Bragg grating including first protrusions each having a first width, and a second Bragg grating including second protrusions each having a second width larger than the first width. Each of the first and second protrusions may include a curved side surface, to which a corresponding one of the optical signals is incident.

A waveguide heater is configured to heat an optical waveguide. The heater includes multiple heating elements and has one or two conditions selected from a group consisting of a first condition and the second condition. The first condition is the heater including multiple interior connectors that are each included in an interior electrical pathway between a pair of the heating elements where the interior connectors are connected in parallel and provide electrical communication between the heating elements included in the pair. The second condition is multiple exterior connectors that are each included in an exterior electrical pathway between electronics and a first one of the heating elements where the exterior connectors are connected in parallel and provide electrical communication between the electronics and the first heating element. The electronics are configured to apply an electrical bias to the heater. In some instances, the heater in included in a wavelength tuner.

A head-up display system and a vehicle are disclosed, the head-up display system comprises a light source and an optical guide assembly (1); an incident light emitted from the light source is incident into the optical guide assembly (1); the optical guide assembly (1) receives the incident light and outputs an exit light; the optical guide assembly (1) comprises at least two optical guides, and the incident light is coupled in and coupled out by the at least two optical guides and then is exited to form at least two divided field of views. By replacing the light guide (4) in the prior art with the optical guide assembly (1), the difficulty for processing a large area optical guide is effectively reduced, and a purpose of expanding an angle of field of view of an HUD and an eyebox is achieved.

Embodiments of the present invention provide optical modules which input and output wavelength multiplexed optical signals to and from an optical waveguide, and a manufacturing method thereof. In one embodiment, an optical module comprises light emitting and light receiving element pairs that are positioned on grooves of one or more optical waveguides, where each light emitting and light receiving element pair corresponds to a different wavelength of light. Each light emitting and light receiving element pair includes an optical pin comprising an inclined surface and a light selecting filter that are configured to reflect light of a corresponding wavelength from an optical waveguide to the light receiving element, and from the light emitting element to the optical waveguide.