Magic Leap, Inc.

Nai-Wen Pi

Vikramjit Singh

Shuqiang Yang

Kang Luo

Frank Y Xu

Xiaopei Deng

Recesses are formed on a front side and a rear side of a waveguide. A solid porogen material is spun onto the front side and the rear side and fills the recesses. First front and rear cap layers are then formed on raised formations of the waveguide and on the solid porogen material. The entire structure is then heated and the solid porogen material decomposes to a porogen gas. The first front and rear cap layers are porous to allow the porogen gas to escape and air to enter into the recesses. The air maximizes a difference in refractive indices between the high-index transparent material of the waveguide and the air to promote reflection in the waveguide from interfaces between the waveguide and the air.

Air pocket structures for promoting total internal reflection in a waveguide

Blazed diffraction gratings provide optical elements in head-mounted display systems to, e.g., incouple light into or out-couple light out of a waveguide. These blazed diffraction gratings may be configured to have reduced polarization sensitivity. Such gratings may, for example, incouple or outcouple light of different polarizations with similar level of efficiency. The blazed diffraction gratings and waveguides may be formed in a high refractive index substrate such as lithium niobate. In some implementations, the blazed diffraction gratings may include diffractive features having a feature height of 40 nm to 120 nm, for example, 80 nm. The diffractive features may be etched into the high index substrate, e.g., lithium niobate.

Display device having diffraction gratings with reduced polarization sensitivity

An eyepiece includes a substrate and an in-coupling grating patterned on a single side of the substrate. A first grating coupler is patterned on the single side of the substrate and has a first grating pattern. The first grating coupler is optically coupled to the in-coupling grating. A second grating coupler is patterned on the single side of the substrate adjacent to the first grating coupler. The second grating coupler has a second grating pattern different from the first grating pattern. The second grating coupler is optically coupled to the in-coupling grating.

Optical eyepiece using single-sided patterning of grating couplers

A method of fabricating a shadow mask includes depositing a chrome etch mask layer on a substrate. The substrate includes a silicon handle wafer, a buried oxide layer, a single crystal silicon layer, and a backside oxide layer. The method also includes forming a patterning layer including a pattern on the chrome etch mask layer, etching the chrome etch mask layer using the patterning layer to transfer the pattern in the patterning layer into the chrome etch mask layer, and etching the pattern of the chrome etch mask layer into the single crystal silicon layer. The method further includes patterning the backside oxide layer, etching the silicon handle wafer using the patterned backside oxide layer, removing the buried oxide layer, and removing remaining portions of the patterned chrome etch mask layer and the patterning layer.

Method and system for tunable gradient patterning using a shadow mask

Embodiments of the present disclosure are directed to techniques for manufacturing an eyepiece (or eyepiece layer) by applying multiple, different diffraction gratings to a single side of an eyepiece substrate instead of applying different gratings to different sides (e.g., opposite surfaces) of the substrate. Embodiments are also directed to the eyepiece (or eyepiece layer) that is arranged to have multiple, different diffraction gratings on a single side of the eyepiece substrate. In some embodiments, two or more grating patterns are superimposed to create a combination pattern in a template (e.g., a master), which is then used to apply the combination pattern to a single side of the eyepiece substrate. In some embodiments, multiple layers of patterned material (e.g., with differing refraction indices) are applied to a single side of the substrate. In some examples, the combined grating patterns are orthogonal pupil expander and exit pupil expander grating patterns.

Superimposed diffraction gratings for eyepieces

A method of depositing a variable thickness material includes providing a substrate and providing a shadow mask having a first region with a first aperture dimension to aperture periodicity ratio and a second region with a second aperture dimension to aperture periodicity ratio less than the first aperture dimension to aperture periodicity ratio. The method also includes positioning the shadow mask adjacent the substrate and performing a plasma deposition process on the substrate to deposit the variable thickness material. A layer thickness adjacent the first region is greater than a layer thickness adjacent the second region.

A method of fabricating a diffractive structure with varying diffractive element depth includes providing a shadow mask having a first region with a first aperture dimension to aperture periodicity ratio and a second region with a second aperture dimension to aperture periodicity ratio less than the first aperture dimension to aperture periodicity ratio. The method also includes positioning the shadow mask adjacent a substrate. The substrate comprises an etch mask corresponding to the diffractive structure. The method further includes exposing the substrate to an etchant, etching the substrate to form diffractive elements adjacent the first region having a first depth, and etching the substrate to form diffractive elements adjacent the second region having a second depth less than the first depth.

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Plano, TX, United States of America

Nai-Wen Pi