An image display device includes an image generating device, a light guide unit, and a light beam expanding device. The light guide unit includes a light guide plate, a first deflector, and a second deflector. The light beam expanding device expands a light beam incident from the image generating device along the Z direction and outputs the light beam to the light guide unit when the incident direction of light incident on the light guide plate is defined as the X direction and the propagation direction of light in the light guide plate is defined as the Y direction. The light beam expanding device is composed of a first reflective mirror on which light from the image generating device is incident and a second reflective mirror on which light from the first reflective mirror is incident and that outputs light to the light guide unit.

A non-reciprocal optical assembly for injection locking a laser to a resonator is described. The laser emits a light beam, and the resonator receives the light beam and returns a feedback light beam to the laser such that the feedback light beam causes injection locking. The non-reciprocal optical assembly is interposed between and optically coupled to the laser and the resonator. The non-reciprocal optical assembly includes a first port that receives the light beam from the laser, and a second port that outputs the light beam to the resonator and receives the feedback light beam from the resonator. The first port also outputs the feedback light beam to the laser. The light beam passes through the non-reciprocal optical assembly with a first power loss, and the feedback light beam passes through the non-reciprocal optical assembly with a second power loss (the first power loss differs from the second power loss).

Systems, devices, and methods for optical engines and laser projectors that are well-suited for use in wearable heads-up displays (WHUDs) are described. Generally, the optical engines of the present disclosure integrate a plurality of laser diodes (e.g., 3 laser diodes, 4 laser diodes) within a single, hermetically sealed, encapsulated package. Such optical engines may have various advantages over existing designs including, for example, smaller volumes, better manufacturability, faster modulation speed, etc. WHUDs that employ such optical engines and laser projectors are also described.

An optical assembly includes a volume grating configured to influence a beam direction of at least one light beam, and a switching device arranged in a beam path upstream of the volume grating. The switching device is configured to switch the beam direction and/or beam position of the at least one light beam from a first beam direction and/or beam position, in which the at least one light beam does not impinge on the volume grating at an acceptance angle of the volume grating, to a second beam direction and/or beam position, in which the at least one light beam impinges on the volume grating at the acceptance angle, and/or vice versa.

A waveguide display includes a display projector for emitting polychromatic image light, and a waveguide assembly for transmitting image light to an exit pupil. The waveguide assembly includes two or more waveguides disposed in a stack, each having an in-coupler aligned with the other in-couplers and an offset out-coupler aligned with the other out-couplers. The assembly is configured so that at least one color channel of the image light propagates to the exit pupil along at least two waveguides. A method for selecting the waveguides of the stack to suppress color channel splitting at the exit pupil is provided.

In various embodiments, alignment systems for laser resonators generate near-field and/or far-field images of input beams produced by the laser resonators to enable the alignment of the input beams.

A light modulating device 103 includes: a selective diffraction device (10, 10′) which generates diffracted light beams of a plurality of orders by diffracting illumination light into one of a plurality of directions, the illumination light being linearly polarized light having a polarization plane oriented in a first polarization direction, and which causes a phase difference between the diffracted light beams of the plurality of orders; and a polarization plane rotating device 14 which rotates the polarization plane of the diffracted light beam of each order so as to be oriented in a direction perpendicular to a direction radiating from an optical axis.

An eyepiece for projecting an image to an eye of a viewer includes a first planar waveguide positioned in a first lateral plane, a second planar waveguide positioned in a second lateral plane adjacent the first lateral plane, and a third planar waveguide positioned in a third lateral plane adjacent the second lateral plane. The first planar waveguide includes a first diffractive optical element (DOE) coupled thereto and disposed at a first lateral position. The second planar waveguide includes a second DOE coupled thereto and disposed at a second lateral position. The third planar waveguide includes a third DOE coupled thereto and disposed at the second lateral position. The eyepiece further includes an optical filter positioned between the second planar waveguide and the third planar waveguide at the second lateral position.

In various embodiments, pointing errors in a non-wavelength-beam-combining dimension of a laser system are at least partially alleviated via staircased collimation lenses.

Disclosed herein is a system and method for facilitating estimation of a spatial profile of an environment based on a light detection and ranging (LiDAR) based technique. In one arrangement, the present disclosure facilitates spatial profile estimation based on directing light over one dimension, such as along the vertical direction. In another arrangement, by further directing the one-dimensionally directed light in another dimension, such as along the horizontal direction, the present disclosure facilitates spatial profile estimation based on directing light in two dimensions.