The future Mixed Reality headset will undoubtedly use waveguides to achieve a spectacle form factor and, if required, optical see-through. Mixed Reality waveguides were unheard of ten years ago, but now they receive billions of dollars in investment. Therefore, while there is a plethora of marketing information online, there is limited information on their theory of operation. This course presents the operating principles of diffractive and reflective waveguides and gives examples of their use in existing MR products. The gratings theory is described for diffractive waveguides, emphasizing the k-space representation. The different grating technologies are then presented, including Volume Bragg Gratings (VBGs), Surface Relief Gratings (SRGs), and Polarization Gratings. Reflective waveguides are described, including their manufacturing methods, advantages over diffractive waveguides, and shortcomings. Finally, the operation of a few existing waveguide-based headsets is described.

Mixed Reality hardware encompasses a wide range of devices to fit specific applications. Characteristics like the optical see-through, field of view, eye box size, and resolution determine each headset's optical design and technology. The display engine is the heart of the optical system as it forms the image and creates an exit pupil for the eye box or the waveguide. This course looks at the two fundamental aspects of display engines: (a) the optical design and (b) the modulator technology forming the image pixels. The first part of the course concentrates on occlusive architectures (VR) with optical designs based on hybrid Fresnel lenses, Catadioptric optics (a.k.a. pancakes) and segmented optics. It continues to describe the basic operation of LCDs and OLED display panels. The second part of the course describes the display engines for optical-see-through architectures (AR), with or without an exit pupil expansion waveguide. The operating principles of Laser Beam Scanners (LBS), Liquid Crystal on Silicon (LCoS), and Digital Micromirrors (DMD) are described, and how they are integrated into the optical system is presented.