A demultiplexed filtering method includes propagating an optical beam from an input optical fiber to a diffraction grating to produce a first and a second diffracted beam having a respective first center wavelength λ.sub.1 and a second center-wavelength λ.sub.2>λ.sub.1 of the optical beam. The first diffracted beam propagates back toward the input optical fiber at a first diffracted angle determined in part by λ.sub.1 and a diffraction order m1 of the first diffracted beam. The second diffracted beam propagates back toward the input optical fiber at a second diffracted angle determined in part by λ.sub.2 and a diffraction order m.sub.2<m.sub.1. The method also includes (i) coupling the first diffracted beam into a first optical fiber of a one-dimensional optical-fiber array that includes the input optical fiber, and (ii) coupling the second diffracted beam into a second optical fiber of the one-dimensional optical-fiber array.

A beam steering method and device are provided. The beam steering method includes outputting, from a hologram recording medium on which a plurality of signal light beams having different steering information are recorded, signal light beam having specific steering information, by making reference light having a specific characteristic incident on the hologram recording medium. The method further includes obtaining information about an object existing in the external environment based on the output signal light.

Implementations disclosed describe a system comprising a first optical device to receive an input beam of light, the input beam having a plurality of spectral components of light, and cause the input beam to disperse into a plurality of spectral beams, wherein each of the plurality of spectral beams corresponds to one of the plurality of spectral components and propagates along a spatial path that is different from spatial paths of other spectral beams, and a second optical device to collect a portion of each of the spectral beams, wherein the collected portion depends on the spatial path of the respective spectral beam, and form an output beam of light from the collected portion of each of the spectral beams, wherein a spectral profile of the output beam is different from a spectral profile of the input beam of light.

An M×N wavelength selective switch (WSS), may comprise a common port fiber array unit (FAU) configured to emit optical beams with a lateral offset and a beam steering device configured to direct optical beams with an angular offset to add/drop port optical fibers of an add/drop port FAU. The common port FAU may comprise a first set of common port optical fibers arranged in a first column of the common port FAU and a second set of common port optical fibers arranged in a second column of the common port FAU. The second column of the common port FAU may be laterally offset from the first column of the common port FAU. The beam steering device may be configured to selectively direct, in two dimensions, the optical beams with the angular offset to the add/drop port optical fibers.

Embodiments include a fiber to photonic chip coupling system including a collimating lens which collimate a light transmitted from a light source and an optical grating including a plurality of grating sections. The system also includes an optical dispersion element which separates the collimated light from the collimating lens into a plurality of light beams and direct each of the plurality of light beams to a respective section of the plurality of grating sections. Each light beam in the plurality of light beams is diffracted from the optical dispersion element at a different wavelength a light beam of the plurality of light beams is directed to a respective section of the plurality of grating sections at a respective incidence angle based on the wavelength of the light beam of the plurality of light beams to provide optimum grating coupling.

Embodiments include a fiber to photonic chip coupling system including a collimating lens which collimate a light transmitted from a light source and an optical grating including a plurality of grating sections. The system also includes an optical dispersion element which separates the collimated light from the collimating lens into a plurality of light beams and direct each of the plurality of light beams to a respective section of the plurality of grating sections. Each light beam in the plurality of light beams is diffracted from the optical dispersion element at a different wavelength a light beam of the plurality of light beams is directed to a respective section of the plurality of grating sections at a respective incidence angle based on the wavelength of the light beam of the plurality of light beams to provide optimum grating coupling.

A display module includes an image light generation device, a light-guiding member, a first reflection surface configured to reflect the imaging light incident via the light-guiding member, a first diffraction element configured to diffract the imaging light, and a second diffraction element configured to diffract the image light and form an exit pupil. The image light is sequentially incident on a first deflection surface, a second deflection surface, a second reflection surface, a third reflection surface, a fourth reflection surface, and a third deflection surface inside the light-guiding member, and a distance from a reference position where an optical axis of the exit pupil and an emission surface intersect to the second deflection surface is longer than a distance from the reference position to the first deflection surface and longer than a distance from the reference position to the second reflection surface.

Methods and systems concerning demultiplexing and multiplexing light in optical multiplexing systems are disclosed herein. An optical multiplexing system may include a number of light emitters and a number of associated waveguides. Light emitted from each of the number of light emitters may travel through the associated waveguide and may enter a multiplexer, where a multiplexing operation may occur. At least one of the number of light emitters may be configured to emit light with multiple wavelengths. Such a light emitter may further be associated with a demultiplexer to demultiplex the light with multiple wavelengths before the light reaches a multiplexer. After a demultiplexing operation, the demultiplexed light may be directed to multiple waveguides and the multiple waveguides may guide the demultiplexed light to a multiplexer.

An on-chip optical switch based on an echelle grating and a phase tuning element is described herein. The phase tuning element may change a refractive index of the material through which an optical signal propagates, thereby causing a change in the angle of propagation of the optical signal. By dynamically tuning the phase change element, the refractive index change may be controlled such that the deviation of the optical signal causes the optical signal to be focused on a particular coupling waveguide out of an array of coupling waveguides. The echelle grating with the active phase change element form a configurable optical switch capable of switching an optical signal between two or more coupling waveguides, that may be respectively connected to different optical signal processing pathways.

An on-chip optical switch based on an echelle grating and a phase tuning element is described herein. The phase tuning element may change a refractive index of the material through which an optical signal propagates, thereby causing a change in the angle of propagation of the optical signal. By dynamically tuning the phase change element, the refractive index change may be controlled such that the deviation of the optical signal causes the optical signal to be focused on a particular coupling waveguide out of an array of coupling waveguides. The echelle grating with the active phase change element form a configurable optical switch capable of switching an optical signal between two or more coupling waveguides, that may be respectively connected to different optical signal processing pathways.