Stefan Alexander (NORTH) on the Argument for Laser Scanning Displays

Stefan Alexander (NORTH) on the Argument for Laser Scanning Displays

Start podcast at 28:49

"One thing that we found out was that for smartglasses, the really important thing is to have everything really small. And when things are small, it drives very certain constraints on the temple arm, and the optics, and the type of combiner technology you're using, and we saw some really hard limits there. And when you put MicroLED in those limits, it doesn't compare very favorably for small displays.

So, I can kind of explain a little bit here. What you need to do in smartglasses, is get a tremendous amount of light into a very, very small area. And, one thing that lasers are outstanding at, is getting a lot of light into a very focused area. And for the optics people, the call this etendue, this is an optical principle where when you have very small, very highly focused sources of light, then they can end up in kind of really small sizes and pixel sizes, whereas where you have larger and more broad sources of light, such as an LED, they cannot go into as small spaces.

So, when you want to have really really small spaces, lasers have an inherent advantage. And what we've found with MicroLED is, it just -- for very small glasses, they're just very very inefficient. And even some of the next generation, generation two or three MicroLED microdisplays that some companies are talking about, where they can control and focus the light a little bit more, this light has to be focused almost to the equivalent point of a laser in order for most of the light to make it to the smartglasses and to the user's eye.

So there's almost a fundamental issue related to some optical principles around where for very very small glasses, and we're talking incredibly small, like what you'd want to see in a normal pair of eyeglasses, where MicroLED just doesn't fit. Even future theoretical, "this is on our five-to-ten year roadmap", kind of magical MicroLEDs that nobody can even really quite make yet, even those don't really compare very favorably to laser when they get really small."

...When MicroLED is compared to laser, when you prioritize size like we do, it just keeps coming up short right now."


Stefan Alexander is the VP of Advanced R&D at North, a company taking a human-centric approach to creating AR smartglass hardware and experiences that are both useful and respectful.