Laser-Bending Chip Could Put A Projector in Your Pocket
Projections of the Letters “CIT” (California Institute of Technology) made with the chip.
Optics researchers have created a tiny chip that creates a projected image without shining a bright light through a small image, and in fact uses no lenses at all. Instead, it uses the physics of light rays to “bend” a laser beam toward where it needs to go — thousands of times per second.
Laser projection isn’t exactly new — anybody who has a DLP home theater setup or has been to a midnight “Laser Pink Floyd” show can tell you that. But those systems rely on mechanical means of moving the laser around — tiny servos and mirrors being tilted many times per second to redirect the beam.
“Our approach does not rely on any mechanical movement and is therefore fundamentally much faster and more reliable in the long term .
It works by taking advantage of light’s wave-like properties. Just as waves in water can add to, subtract from, and bounce off of one another, light can be made to interfere with itself as well.
The optical phased array chip.
The “optical phased array” chip uses a laser and a series of light guides to project waves of light that are precisely configured to send a pulse of light in a very specific direction. Essentially the laser light is being broken apart and recohered — but going somewhere else. The process takes only nanoseconds.
“This chip is just a prototype to prove the concept,” but the chip, just a millimeter square, could eventually be made to produce large, bright images — either by scanning across every pixel in an image, like a laser projector, or by “drawing” the image, like what you’d see at a laser show.
With no lens, very little electronics, and no moving parts, the chip has a lot of advantages over current projection technology — though it’s still at an early stage. The research was performed by Hajmiri, Firooz Aflatouni, Behrooz Abiri, and undergraduate Angad Rekhi at Caltech.