In the future, producing an exact copy of an object with a 3D printer could become easier, faster and even cheaper. A team of researchers at Caltech discovered a new device that could replace the current systems in 3D imaging which are generally too large and a bit pricey to be used in consumer applications. With the new device, one can simply pull his smartphone, take a snapshot using the phone's integrated 3D imager, send the image to one's 3D printer and reproduce an accurate replica of the image.
Regular cameras usually have pixels that simply represent the intensity of the light that is received from a certain point in the image. Such point could be either near or far from the camera. However, these pixels don't give information on the object's relative distance from the camera.
The team of researchers at Caltech discovered that a new device known as Nanophotonic Coherent Imager (NCI) can provide both information on intensity and distance. By using a cheaper silicon chip, smaller than a millimeter square, the NCI becomes capable enough to provide the highest accuracy in terms of depth-measurement that is normally produced by any nanophotonic 3D imaging device.
"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," said Ali Hajimiri, professor of Electrical Engineering at Caltech.
The new NCI chip incorporates the ranging and detection technology known as LIDAR which is used to gather information on the target object's size and distance from the laser light used in order to produce an image of its surroundings. Such information had actually been analyzed according to the wavelength of the laser light that was used to illuminate the target object.
The team's research paper says: "The proposed NCI uses time-domain signal detection and processing of this electrical output to resolve the relative phase and power of the incident wave at each pixel. This simultaneously enables high depth resolution and large dynamic range, overcoming some of the limitations of conventional frequency domain FMCW (frequency modulated continuous wave) approaches."
In the paper's conclusion, the team stated "Using the implemented integrated NCI, we have conducted high resolution index of refraction contrast imaging, 3D transmissive, and 3D reflective imaging. Use of silicon photonics platform enables realization of NCIs with large number of pixels making low-cost high performance NCIs available for varieties of applications in the near future."
These applications can range from highly accurate 3D scanning and printing to collision-prevention among driverless cars and enhanced motion sensitivity in ultrafine human machine interfaces. The latter can come in handy when there's a need to quickly detect certain bodily movements and changes such as the movement of a patient's eye and changes in his heartbeat.
"The small size and high quality of this new chip-based imager will result in significant cost reductions, which will enable thousands (of new uses) for such systems by incorporating them into personal devices such as smartphones," added Hajimiri.
Photo: Karlis Dambrans I Flickr
