Display devices include waveguides with in-coupling optical elements that mitigate re-bounce of in-coupled light to improve overall in-coupling efficiency and/or uniformity. A waveguide receives light from a light source and/or projection optics and includes an in-coupling optical element that in-couples the received light to propagate by total internal reflection in a propagation direction within the waveguide. Once in-coupled into the waveguide the light may undergo re-bounce, in which the light reflects off a waveguide surface and, after the reflection, strikes the in-coupling optical element. Upon striking the in-coupling optical element, the light may be partially absorbed and/or out-coupled by the optical element, thereby effectively reducing the amount of in-coupled light propagating through the waveguide. The in-coupling optical element can be truncated or have reduced diffraction efficiency along the propagation direction to reduce the occurrence of light loss due to re-bounce of in-coupled light, resulting in less in-coupled light being prematurely out-coupled and/or absorbed during subsequent interactions with the in-coupling optical element.

Disclosed are apparatus and methods for optical coupling. In one example, a described apparatus includes: a planar layer; a grating region comprising an array of scattering elements arranged in the planar layer to form a two-dimensional grating; a first taper structure formed in the planar layer connecting a first side of the grating region to a first waveguide, wherein a shape of the first taper structure is a first triangle that is asymmetric about any line perpendicular to the first side of the grating region in the planar layer; and a second taper structure formed in the planar layer connecting a second side of the grating region to a second waveguide, wherein a shape of the second taper structure is a second triangle that is asymmetric about any line perpendicular to the second side of the grating region in the planar layer, wherein the first side and the second side are substantially perpendicular to each other.

Disclosed are apparatus and methods for optical coupling. In one example, a described apparatus includes: a planar layer; a grating region comprising an array of scattering elements arranged in the planar layer to form a two-dimensional grating; a first taper structure formed in the planar layer connecting a first side of the grating region to a first waveguide, wherein a shape of the first taper structure is a first triangle that is asymmetric about any line perpendicular to the first side of the grating region in the planar layer; and a second taper structure formed in the planar layer connecting a second side of the grating region to a second waveguide, wherein a shape of the second taper structure is a second triangle that is asymmetric about any line perpendicular to the second side of the grating region in the planar layer, wherein the first side and the second side are substantially perpendicular to each other.

There is provided an optical system, including a light-transmitting substrate (20) having at least two external major surfaces and edges, an optical element for coupling light waves into the substrate (20) by internal reflection, at least one partially reflecting surface located in the substrate (20), for coupling light waves out of the substrate (20), at least one transparent air gap film (110) including a base (112) and a hyperfine structure (111) defining a relief formation, constructed on the base, wherein the air gap film is attached to one of the major surfaces of the substrate (20), with the relief formation facing the substrate (20) defining an interface plane (58), so that the light waves coupled inside the substrate (20) are substantially totally reflected from the interface plane (58).

There is provided an optical system, including a light-transmitting substrate (20) having at least two external major surfaces and edges, an optical element for coupling light waves into the substrate (20) by internal reflection, at least one partially reflecting surface located in the substrate (20), for coupling light waves out of the substrate (20), at least one transparent air gap film (110) including a base (112) and a hyperfine structure (111) defining a relief formation, constructed on the base, wherein the air gap film is attached to one of the major surfaces of the substrate (20), with the relief formation facing the substrate (20) defining an interface plane (58), so that the light waves coupled inside the substrate (20) are substantially totally reflected from the interface plane (58).

Systems and methods for providing holographic waveguide display using integrated gratings in accordance with various embodiments of the invention are illustrated. One embodiment includes a waveguide display including a source of light, and a first waveguide including a grating structure including first and second gratings, and an input coupler configured to couple a first field-of-view portion of light, and couple a second field-of-view portion of light, wherein the first grating is configured to provide beam expansion in a first direction for the first field-of-view portion of light, and provide beam expansion in the first direction and beam extraction towards a viewer for the second field-of-view portion of light, the second grating is configured to provide beam expansion in a second direction for the second field-of-view portion of light, and provide beam expansion in the second direction and beam extraction towards a viewer for the first field-of-view portion of light.

Systems and methods for providing holographic waveguide display using integrated gratings in accordance with various embodiments of the invention are illustrated. One embodiment includes a waveguide display including a source of light, and a first waveguide including a grating structure including first and second gratings, and an input coupler configured to couple a first field-of-view portion of light, and couple a second field-of-view portion of light, wherein the first grating is configured to provide beam expansion in a first direction for the first field-of-view portion of light, and provide beam expansion in the first direction and beam extraction towards a viewer for the second field-of-view portion of light, the second grating is configured to provide beam expansion in a second direction for the second field-of-view portion of light, and provide beam expansion in the second direction and beam extraction towards a viewer for the first field-of-view portion of light.

An example a head-mounted display device includes a light projector and an eyepiece. The eyepiece is arranged to receive light from the light projector and direct the light to a user during use of the wearable display system. The eyepiece includes a waveguide having an edge positioned to receive light from the display light source module and couple the light into the waveguide. The waveguide includes a first surface and a second surface opposite the first surface. The waveguide includes several different regions, each having different grating structures configured to diffract light according to different sets of grating vectors.

An optical waveguide includes an optical waveguide body having a beam in-coupling region and a beam coupling-out region, wherein: the beam in-coupling region is provided with a coupling grating configured to couple a beam into the optical waveguide body, and have the beam propagate in a total reflection manner in the optical waveguide body; the beam coupling-out region is provided with an out-coupling grating configured to couple the light beam propagating to the beam coupling-out region out of the optical waveguide body, such that the beam does not undergo secondary diffraction at the coupling grating and have continuous exit pupil expansion; and the out-coupling grating includes a transmissive out-coupling grating and a reflective out-coupling grating disposed on two sides of the optical waveguide body parallel to a beam propagation direction.

A system includes a plurality of wafer-scale modules and a plurality of optical fibers. Each wafer-scale module includes an optical backplane and one or more die stacks on the optical backplane. The optical backplane includes a substrate and at least one optical waveguide layer configured to transport and/or manipulate photonic quantum systems (e.g., photons, qubits, qudits, large entangled states, etc.). Each die stack of the one or more die stacks includes a photonic integrated circuit (PIC) die optically coupled to the at least one optical waveguide layer of the optical backplane. The plurality of optical fibers is coupled to the optical backplanes of the plurality of wafer-scale modules to provide inter-module and/or intra-module interconnects for the photonic quantum systems.