Tomas Sluka | CREAL: What optical trade-offs occur when using a 0.8mm mirror and coherent lasers in waveguide-based AR displays?
15:31 - 17:12
Other snippets from this talk
Summary of the clip:
What optical trade-offs occur when using a 0.8mm mirror and coherent lasers in waveguide-based AR displays?
The 0.8 millimetre mirror is a pupil of the optics. A 1.2 millimetre mirror was already made and more or less allows the needed MTF, getting below the waveguide limit. The 0.8 millimetre version looks really good, but speed is the fight: making the mirror bigger makes it slower. An eight kilohertz quasi-static mirror is needed for that.
The waveguide pupil replication concern is real with such a small pupil size. Using a coherent light source and hard edge pupils, are you getting holes in the eye box? It is horrible. The exchange acknowledges this and raises whether a really thin waveguide is needed. Even on that small image, there are many artifacts coming from the lasers. It is a lab demo, and the waveguides are optimized for a much bigger pupil.
Most recent waveguides are optimized for micro LEDs, which are huge. The suggestion is to test the small-pupil approach, because a small pupil would actually bring a lot of benefits if the waveguide was designed that way. In this laser session, the exchange says this would benefit from sLEDs, and calls it kind of bad laser. That is the trade-off: small pupil, coherent source, and pupil replication.
In this short video, you can learn:
* A 0.8 millimetre mirror acts as the optics pupil, while a 1.2 millimetre mirror more or less reaches the needed MTF below the waveguide limit.
* Speed forces the choice: a bigger mirror is not as fast, and an eight kilohertz quasi-static mirror is required.
* Coherent lasers and small pupils create hard edge pupils and eye-box holes, with laser artifacts still visible in the lab demo while waveguides remain optimized for much bigger micro LED pupils.
📋 **Clip Abstract** Using a 0.8 millimetre mirror as the optics pupil creates a waveguide pupil replication problem with coherent lasers, producing hard edge pupils and holes in the eye box. A 1.2 millimetre mirror more or less meets the needed MTF below the waveguide limit, but speed requires an eight kilohertz quasi-static mirror, and current waveguides optimized for much bigger micro LED pupils still show laser artifacts in the lab demo.
About the speaker:
* Speaker: Tomas Sluka
* Company: CREAL
* Event: Eindhoven 2026
* Location: High Tech Campus, Eindhoven
#WaveguidePupilReplication, #CoherentLightSource, #HardEdgePupils, #EyeBoxHoles, #ARDisplays, #LaserDisplays
This is a highlight of the presentation:
Time-Sequential Pixel Replication: How Laser-FLCoS Breaks the Resolution-FoV Barrier in AR
More Highlights from the same talk.
03:42 - 05:29
Why does stabilizing an AR image require spare pixels, high frame rate, short persistence and high peak brightness?
Why does stabilizing an AR image require spare pixels, high frame rate, short persistence and high peak brightness?
Moving the image to counteract head movement stabilizes it, so part of the problem is solved. But a new one appears: the small display becomes too small because spare pixels must surround the image, giving it somewhere to move. Even for just an arrow or a letter, the image must move on the display for stabilization. Increasing field of view can improve the limited-size problem, yielding enough pixels to move the image and keep it stable.
The first fix means quite high frame rate is needed. Not only frame rate: high frame rate, short image persistence and high peak brightness in notoriously low efficiency optics. If high frame rate is available, the image will stabilize. For spare pixel area and field of view, just put more pixels, basically creating more, smaller and brighter pixels. Many talks at this conference indicate this is a critical problem.
The chain is clear: image movement for stabilization creates a spare-pixel area around the image. That area forces either a larger field of view or more pixels. More pixels then mean smaller brighter pixels. High frame rate, short image persistence and high peak brightness must all coexist with low efficiency optics. The result is a critical problem, as many talks at the conference indicate.
In this short video, you can learn:
* Moving the image to counteract head movement stabilizes it but requires spare pixels around the image on the display.
* Increasing field of view supplies enough pixels for image movement, yet demands high frame rate, short image persistence and high peak brightness in low efficiency optics.
* The remaining approach is more, smaller and brighter pixels, which the conference talks identify as a critical problem.
📋 **Clip Abstract** Moving the image to counteract head movement stabilizes the displayed image but makes a small display too small because spare pixels must surround the image, even for an arrow or letter. The response is higher field of view and more pixels, but this demands high frame rate, short image persistence, high peak brightness in notoriously low efficiency optics, and more smaller, brighter pixels.
About the speaker:
* Speaker: Tomas Sluka
* Company: CREAL
* Event: Eindhoven 2026
* Location: High Tech Campus, Eindhoven
#SparePixelArea, #ShortImagePersistence, #HighPeakBrightness, #LowEfficiencyOptics, #AROptics, #DisplayArchitecture
08:29 - 10:49
How can a fast FLCOS display create a 3K image from a 1K footprint?
How can a fast FLCOS display create a 3K image from a 1K footprint?
The design work started from the field-of-view direction: the display is fast enough to create multiple sections of the field of view simultaneously. It can show up to seven colored sections without flicker, and technically nine. A near-term AR use case uses the simple mode most of the time, but stabilized: the image hangs in the air, not shaking. Notifications can appear left and right within a 70-degree field of view, described as 25, 25, 25.
When you are plugged into power and compute, the same device can fill the full field of view, either short term or longer. The approach creates a world-locked, body-locked experience: the image hangs in the air rather than shaking. It can bring a wide field of view from around 30 times smaller footprint than brute force would require. That means a 3K display from a 1K footprint.
For FLCOS, which has smaller problems with making the pixel smaller because the limit is kind of 1.5 micron—at least this was tested—the approach can do 2.8 micron. The reason is simpler electronics, a thinner LC layer, and smaller cross-talk between pixels running at high speed. So the display can extend that sound barrier. We did not cross the sound barrier; we changed the environment.
In this short video, you can learn:
* The FLCOS display can create up to seven colored field-of-view sections without flicker, and technically nine.
* A 70-degree field of view can show notifications left and right, described as 25, 25, 25, while the same device fills the full field of view when plugged into power and compute.
* The approach delivers a 3K display from a 1K footprint, around 30 times smaller than brute force, using 2.8-micron pixels versus a tested 1.5-micron limit.
📋 **Clip Abstract** The clip explains using a fast FLCOS display to create multiple field-of-view sections simultaneously, up to seven colored without flicker and technically nine. It describes a stabilized world-locked AR experience, a 70-degree field of view with 25,25,25 notifications, a 3K display from a 1K footprint, and 2.8-micron pixels enabled by simpler electronics, a thinner LC layer, and smaller cross-talk.
About the speaker:
* Speaker: Tomas Sluka
* Company: CREAL
* Event: Eindhoven 2026
* Location: High Tech Campus, Eindhoven
#FLCOS, #PixelCrossTalk, #ThinnerLCLayer, #3KFrom1KFootprint, #ARDisplays, #NearEyeDisplays
06:33 - 08:15
How does an 8 kHz SLCoS modulator plus MEMS stabilize AR images with essentially no compute overhead?
How does an 8 kHz SLCoS modulator plus MEMS stabilize AR images with essentially no compute overhead?
The approach is a light-source modulator system: a laser with an SLCoS high frame rate liquid crystal modulator running at eight kilohertz. It can be made or worked on a 2.8 micron pixel pitch version and is combined with a MEMS. These components were already developed and used for a light field system, which works beautifully for vision care and medical application. They are unique because of the protocol needed to drive them.
First, it can do what other displays do: create an image in 25 degrees field of view. At 1K by 1K, that gives around 40 PPD, matching most of the resolution of waveguides or the NTF of the waveguides. On top of that, it can move the image a bit left, a bit right. There is an alert or indication. You can use it to stabilize against movement with practically any compute overhead.
If we forget about color corrections, no compute is required at all; it can be analog in fact. That is how the image then looks. The components first create the image, then shift it left or right for stabilization with practically any compute overhead. They are already developed and used for a light field system.
In this short video, you can learn:
* An eight kilohertz liquid crystal modulator with 2.8 micron pixel pitch is combined with MEMS for this light-source modulator system.
* A 1K by 1K image in a 25 degree field of view yields around 40 PPD, matching most waveguide resolution or NTF.
* The same system can shift the image left or right to stabilize against movement with practically any compute overhead, and without color corrections no compute is required.
📋 **Clip Abstract** The clip describes a light-source modulator system: an eight kilohertz liquid crystal modulator at 2.8 micron pixel pitch, combined with MEMS and already used for a light field system in vision care and medical applications. It creates a 1K by 1K image in a 25 degree field of view at around 40 PPD, then shifts the image left or right to stabilize against movement with practically any compute overhead, and without color corrections no compute is required.
About the speaker:
* Speaker: Tomas Sluka
* Company: CREAL
* Event: Eindhoven 2026
* Location: High Tech Campus, Eindhoven
#SLCoS, #MEMS, #LiquidCrystalModulator, #ZeroComputeStabilization, #ARDisplays, #NearEyeDisplays