Two-dimensional imaging is limited in that it cannot provide depth perception. One can view objects in the distance, but cannot determine how far away these images are. Three-dimensional imaging, such as RADAR, can accomplish this, but radio wavelengths are too long to provide detailed resolution. LIght Detection And Ranging (LIDAR) uses optical wavelengths, providing easily four orders of magnitude better resolution, allowing the imaging of sub-millimeter detail or better. However, the conventional LIDAR method employs short optical pulses that need high-speed, 2-D photodetection, which is prohibitively expensive. Our method uses a low-speed swept laser wavelength that creates a time delay proportional to the distance of the imaged objects. When heterodyned with a reference beam, the time delay creates a wavelength difference which will be proportional to the object distance. This beat frequency can be detected with much slower speed 2-D detector arrays, drastically reducing the system cost and opening up applications in the consumer market.
Project end date: 02/02/11