The immersive virtual reality (VR) and the optical see-through augmented reality (AR) are expected to revolutionize human lives in work, education, entertainment, healthcare, spatial computing, and digital twins, just to name a few. Next-generation VR/AR devices should exhibit a wide field-of-view (FoV), crisp image without screen-door effect, high dynamic range, compact form factor and lightweight, and low power consumption. Such demanding requirements pose a significant challenge to traditional direct-view display panels. To address these technical challenges, novel approaches need to be proposed. This dissertation is devoted to developing next-generation high-performance display light engines toward high resolution density, high optical efficiency, wide color gamut, and small form factor. These emerging solutions will fuel the growth and accelerate the widespread applications of VR/AR devices. In Chapter 2, we propose practical measurement methods to characterize the halo artifacts of miniature light-emitting diode (mini-LED) backlit liquid crystal displays (LCDs). After measuring and characterizing a high dynamic range (HDR) light engine, we propose and develop field sequential color (FSC) LCDs for high-end virtual reality (VR) devices in Chapter 3. Such an FSC LCD can triple the resolution density and optical efficiency via eliminating color filters. To further mitigate the color breakup (CBU), we also propose to combine mini-LEDs with FSC LCDs to enable progressive emission and achieve a higher frame rate (~ 600 Hz). To quantitatively compare the CBUs corresponding to simultaneous emission, progressive emission, and stencil algorithm, we adopt the CIEDE2000 color difference as a metric. Quantitative simulation results of the CBU indicate that a 600-Hz subframe rate can help mitigate the CBU dramatically. Micro organic light-emitting diode (micro-OLED) exhibiting high-resolution density and high contrast ratio is another type of display for high-end VR devices. More specifically, white micro-OLED is currently employed because it helps ease the manufacturing difficulty. In Chapter 4, we optimize the layer thicknesses to achieve a maximum efficiency while keeping a decent color gamut. We also push the limit of color gamut toward ~ 95% Rec. 2020. Lastly, liquid-crystal-on-silicon (LCoS) offers great potential for achieving high-efficiency and high-resolution waveguide-based AR displays. In Chapter 5, several strategies are proposed and developed to improve the performance of LCoS microdisplays and enable a small pixel size. In Chapter 6, we briefly summarize our major accomplishments.

Low power consumption is a critical requirement for all liquid crystal display (LCD) devices. A field sequential color (FSC) LCD was proposed by using red (R), green (G) and blue (B) LEDs and removing the lossy component of color filters which only transmits ~30% of the incoming white light. Without color filters, FSC LCDs exhibit a ~3X higher optical efficiency and 3X higher resolution density as compared to the conventional color filters-based LCDs. However, color breakup (CBU) is a most disturbing defect that degrades the image quality in FSC displays. CBU can be observed in stationary or moving images. It manifests in FSC LCDs when there is a relative speed between the images and observers’ eyes, and the observer will see the color splitting patterns or rainbow effect at the boundary between two different colors. In Chapter 2, we introduce a five-primary display by adding additional yellow(Y) and cyan(C) colors. From the analysis and simulations, five primaries can provide wide color gamut and meanwhile the white brightness is increased, as compared to the three-primary. Based on the five-primary theorem, we propose a method to reduce CBU of FSC LCDs by using RGBYC LEDs instead of RGB LEDs in the second section. Without increasing the sub-frame rate as three-primary LCDs, we can reduce the CBU by utilizing proper color sequence and weighting ratios. In addition, the color gamut achieves 140% NTSC and the white brightness increases by more than 13%, as compared to the three-primary FSC LCDs. Another strategy to suppress CBU is using higher field frequency, such as 540 Hz or even up to 1000 Hz. However, this approach needs liquid crystals with a very fast response time (