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

A near eye or heads up display system includes a display engine, at least two optical waveguides, and a respective coating on at least one of the major surfaces of at least one of the waveguides. At least one such coating has a low reflectance for light within a specific wavelength range for the waveguide and incident on a major surface of the waveguide on which the coating is located at an angle below a low threshold angle relative to a normal, and has a high reflectance for light within the specific wavelength range for the waveguide that is incident on the major surface on which the coating is located at an angle above a high threshold angle relative to the normal.

Some embodiments relate to an optical module including a substrate; a first grating coupler overlying the substrate; and a second grating coupler overlying the first grating coupler, where the second grating coupler is configured to receive a first transverse mode of an input optical signal while passing a second transverse mode of the input optical signal to the first grating coupler, and where the first grating coupler is configured to receive the second transverse mode of the input optical signal.

Providing an image extraction section with a plurality of video light reflection surfaces that are Fresnel-shaped reflection surfaces allows reduction in the thickness of a light guide apparatus and hence the thickness and size of a virtual image display apparatus. In particular, providing a dispersion elimination section for eliminating wavelength dispersion in correspondence with the image extraction section suppresses image deterioration resulting from dispersion (chromatic aberrations) on a wavelength band basis.

An apparatus including a waveguide region configured to guide light propagating along a first direction; a reflector region configured to reflect incident light; an interference region formed between the waveguide region and the reflector region, the interference region configured to confine at least a portion of interference light formed by the incident light and the reflected incident light; and a grating region including a grating formed on a region confining at least a portion of the interference light, the grating configured to couple at least a portion of the light along a second direction that is different from the first direction.

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.

The present application discloses a system comprising a compact curved grating (CCG) and its associated compact curved grating spectrometer (CCGS) or compact curved grating wavelength multiplexer/demultiplexer (WMDM) module and a method for making the same. The system is capable of achieving a very small (resolution vs. size) RS factor. The location of the entrance slit and detector can be adjusted in order to have the best performance for a particular design goal. The initial groove spacing is calculated using a prescribed formula dependent on operation wavelength. The location of the grooves is calculated based on two conditions. The first one being that the path-difference between adjacent grooves should be an integral multiple of the wavelength in the medium to achieve aberration-free grating focusing at the detector or a first anchor output slit even with large beam diffraction angle from the entrance slit or input slit, the second one being specific for a particular design goal of a curved-grating spectrometer.

A demultiplexer for use in a wavelength division multiplexed system. The demultiplexer comprises: an input waveguide, configured to receive a wavelength division multiplexed signal; a demultiplexing element, configured to demultiplex the multiplexed signal received from the input waveguide into a plurality of multi-mode demultiplexed signal components; a multi-mode output waveguide, the multi-mode output waveguide being coupled to the demultiplexing element and configured to receive one of the multi-mode demultiplexed signal components; and a splitter, coupled to the multi-mode output waveguide, and configured to split the received multi-mode demultiplexed signal component into two single-mode outputs.

Providing an image extraction section with a plurality of video light reflection surfaces that are Fresnel-shaped reflection surfaces allows reduction in the thickness of a light guide apparatus and hence the thickness and size of a virtual image display apparatus. In particular, providing a dispersion elimination section for eliminating wavelength dispersion in correspondence with the image extraction section suppresses image deterioration resulting from dispersion (chromatic aberrations) on a wavelength band basis.

An augmented reality headset includes a projector and an eyepiece waveguide stack optically coupled to the projector. The eyepiece waveguide stack includes: a first eyepiece waveguide including a first incoupling diffractive optical element and a first combined pupil expander; and a second eyepiece waveguide including a second incoupling diffractive optical element and a second combined pupil expander. The second incoupling diffractive optical element is laterally offset from the first incoupling diffractive optical element in a lateral direction.