Assaf Levy-Beeri | Joya Team: Why does your choice of waveguide—geometric, diffractive, or holographic—dictate which microdisplay technology you can even use?
12:00 - 14:33
Other snippets from this talk
Summary of the clip:
Why does your choice of waveguide—geometric, diffractive, or holographic—dictate which microdisplay technology you can even use?
The speaker analyzes the critical compatibility between different microdisplay technologies and the main optical architectures used in AR. For simpler "birdbath" combiners and geometric waveguides (which rely on conventional reflection and refraction), emissive displays like OLED and MicroLED are excellent choices. Their characteristics allow for straightforward integration into these optical systems, with LCoS also being a viable option for geometric waveguides.
A crucial technical distinction arises when dealing with diffractive and holographic waveguides. These advanced optical elements function based on the principles of diffraction and are extremely sensitive to the spectral bandwidth (the range of wavelengths) of the light source. Laser Beam Scanning (LBS) is identified as the most optimal technology for these systems because it uses laser diodes that produce a very narrow, nearly monochromatic, spectral output, which is essential for high efficiency and performance in diffractive optics.
This presents a significant challenge for MicroLEDs in this context. The light emitted from a MicroLED has a much wider spectral bandwidth compared to a laser. When coupled with a diffractive or holographic waveguide, this wider bandwidth leads to significant light loss and poor efficiency, as much of the light will not be diffracted at the correct angle. Furthermore, this lost light can scatter within the waveguide, creating stray light and visual artifacts that degrade the final image quality for the user.
In this short video, you can learn:
* Which microdisplay technologies are best suited for birdbath and geometric waveguides.
* The critical role of spectral bandwidth when designing for diffractive and holographic waveguides.
* Why Laser Beam Scanning (LBS) has a fundamental performance advantage over MicroLED for diffractive systems.
📋 **Clip Abstract** This clip details the crucial interplay between microdisplay light sources and AR optical architectures like waveguides. The speaker explains why emissive displays like MicroLED excel with geometric waveguides, while the narrow spectral bandwidth of LBS is a key enabler for diffractive and holographic systems.
🔗 Link in comments 👇
#ARWaveguides, #MicrodisplayCompatibility, #SpectralBandwidth, #DiffractiveOptics, #AugmentedReality, #WearableDisplays
This is a highlight of the presentation:
MicroLED in AR Systems: Bridging Technology and Market Needs
MicroLEDs, AR/VR Displays, Micro-Optics 2025: Innovations, Start-Ups, Market Trends
Online | TechBlick platform
Organised By:
TechBlick
MicroLED Connect
More Highlights from the same talk.
09:01 - 11:56
LBS, DLP, LCoS, OLED, or MicroLED... which microdisplay reigns supreme for AR, and why is the "best" choice not always the obvious one?
LBS, DLP, LCoS, OLED, or MicroLED... which microdisplay reigns supreme for AR, and why is the "best" choice not always the obvious one?
This segment provides a detailed technical comparison of the primary microdisplay technologies used in AR headsets. Laser Beam Scanning (LBS) offers a compact design and high luminance but often falls short on image quality, specifically contrast ratio and resolution. DLP technology, while capable, leads to complex and bulky projection optics, making it less suitable for the sleek form factors desired in consumer AR glasses.
LCoS stands out as a cost-competitive technology, but it shares a significant drawback with DLP: it requires a complex external illumination system and careful polarization management, which adds to the overall system size and complexity. Surprisingly, even mature technologies like LCDs find a niche in high-end defense headsets. These systems prioritize extreme brightness for outdoor use and can tolerate the high cost and compromises in other performance areas like contrast and color gamut.
OLED technology is a favorite for many AR developers because it is emissive, simplifying the optical design and offering excellent contrast. However, its primary limitations are its peak luminance and operational lifetime, especially at high brightness levels. The core expectation for MicroLED is that it will deliver the key advantages of OLED—such as simple integration and high contrast—while decisively overcoming its weaknesses in brightness and longevity.
In this short video, you can learn:
* The specific pros and cons of six major microdisplay technologies for AR.
* Why reflective technologies like LCoS and DLP have more complex optical integration requirements.
* How MicroLED aims to combine the advantages of OLED while overcoming its key limitations.
📋 **Clip Abstract** This clip delivers a comprehensive technical comparison of the six leading microdisplay technologies for AR headsets, from LBS to MicroLED. The speaker analyzes the critical trade-offs between performance, cost, and system integration complexity for each option.
🔗 Link in comments 👇
#ARMicrodisplays, #MicroLEDDisplays, #OLEDMicrodisplays, #LCoSMicrodisplays, #WearableElectronics, #AugmentedReality
16:57 - 17:57
Beyond brightness and efficiency, what's the one overlooked parameter that could make MicroLEDs the ultimate display for AR systems?
Beyond brightness and efficiency, what's the one overlooked parameter that could make MicroLEDs the ultimate display for AR systems?
A key, and often underappreciated, technical parameter for AR light engines is the control of the light's emission angle. A typical AR optical system, particularly one employing a waveguide, is designed to accept and guide light only within a very specific and narrow angular cone. This acceptance angle is often limited to just plus or minus 20 degrees from the central axis.
Any photon emitted from the microdisplay outside of this narrow acceptance cone is effectively wasted energy, contributing nothing to the final image seen by the user. More critically, this "wasted" light doesn't simply vanish; it can scatter within the optical assembly, becoming a significant source of stray light. This stray light manifests as haze or ghosting, which severely degrades image contrast and the overall visual experience.
This physical constraint presents a unique opportunity for MicroLED technology to gain a significant competitive advantage. Unlike OLEDs, which are typically Lambertian emitters that radiate light over a wide 180-degree hemisphere, the physical structure of a microLED pixel can be engineered to shape its emission pattern. If microLED developers can design pixels that collimate the light into a narrow cone matching the AR optics, it would dramatically improve system efficiency and reduce image-degrading artifacts.
In this short video, you can learn:
* Why AR optics can only utilize light from a narrow angular cone (e.g., ±20 degrees).
* How light emitted outside this cone becomes wasted energy and creates visual artifacts.
* The potential for MicroLEDs to be engineered with a controlled, narrow viewing angle, giving them a key system-level advantage.
📋 **Clip Abstract** The speaker reveals a critical optimization for AR displays: controlling the viewing angle of the light source to match the optical system's acceptance cone. He advises MicroLED developers that engineering pixels with a narrow, directed light emission would be a significant technical advantage over other display technologies.
🔗 Link in comments 👇
#MicroLEDs, #LightCollimation, #ARWaveguides, #OpticalEfficiency, #AugmentedReality, #WearableElectronics