To boost the storage capacity of tomorrow's computers, information is digitally recorded on optical disks and read by a laser. Scientists hoped to enhance the computers memory banks even further by stacking several optical disks on top of each other. However, information retrieval from such systems is relatively slow because the laser can only focus on one level at a time.
Dr. Erez Hasman and Prof. Asher Friesem of the Weizmann Institute's Physics of Complex Systems Department have developed an approach that may greatly speed up this process by reading multiple layers simultaneously. It also reduces the amount of light signals containing unwanted information, referred to as background noise, relative to the signals with the useful information.
The new method employs a number of light sources, such as diode lasers, which emit several light beams of different wavelengths. These beams are radiated onto the different optical disks simultaneously using a novel optical element. The reflected light is then analyzed according to wavelength, providing information about each disk.
While optical disks can now store up to 650 megabytes of data, the new approach may push their storage capacity to thousands of megabytes. A patent was recently registered in the U.S.A. by Yeda Research and Development Co. Ltd., which handles the commercial development of Weizmann Institute research.
Prof. Friesem holds the Peter and Carola Kleeman Chair of Optical Sciences.
The Weizmann Institute of Science is a major center of scientific research and graduate study located in Rehovot, Israel.