Nanophotonic Coherent Imagers Are Super-accurate 3D Cameras
Is super accurate 3D scanning from a smartphone possible? It may be sson if this chip becomes mainstream...
Using an inexpensive silicon chip less than a millimeter square in size, the NCI (Nanophotonic Coherent Imager) provides the highest depth-measurement accuracy of any such nanophotonic 3-D imaging device. The work, done in the laboratory of Ali Hajimiri, the Thomas G. Myers Professor of Electrical Engineering in the Division of Engineering and Applied Science, is described in the February 2015 issue of Optics Express.
The micrometer-resolution image, taken from roughly half a meter (1.5 feet)
away, shows the height of a US penny at various points. Credit: Ali Hajimiri/Caltech
How it works
In a regular camera, each pixel represents the intensity of the light received from a specific point in the image, which could be near or far from the camera—meaning that the pixels provide no information about the relative distance of the object from the camera. In contrast, each pixel in an image created by the Caltech team's NCI provides both the distance and intensity information. "Each pixel on the chip is an independent interferometer—an instrument that uses the interference of light waves to make precise measurements—which detects the phase and frequency of the signal in addition to the intensity," says Hajimiri.
The new chip utilizes an established detection and ranging technology called LIDAR, in which a target object is illuminated with scanning laser beams. The light that reflects off of the object is then analyzed based on the wavelength of the laser light used, and the LIDAR can gather information about the object's size and its distance from the laser to create an image of its surroundings. "By having an array of tiny LIDARs on our coherent imager, we can simultaneously image different parts of an object or a scene without the need for any mechanical movements within the imager," Hajimiri says.
Source : Phys.org.