Optical Phased Array Chip Acts As A Lens-Free Projector
Traditional projectors - like those used to project a film - pass a beam of light through a tiny image, using lenses to map each point of the small picture to corresponding, yet expanded, points on a large screen. A new chip, developed by electrical engineering professor Ali Hajimiri of the California Institute of Technology, eliminates the need for bulky and expensive lenses and bulbs and instead uses an integrated optical phased array (OPA) to project the image electronically with a single laser diode as light source and no mechanically moving parts. In this video, the letters 'C,' 'I,' and 'T' are projected using Hajimiri's optical phased array chip. The images shown are projected in infrared light. A tiny projection device can have many applications, including light-based radar systems (LIDAR), which are used in positioning, robotics, geographical measurements, and mapmaking.