Volume 11, Number 2 • Summer 2003 • Small Business/SBIR

SLM Technology Creates New Commercial Opportunities

The light square in the center is a 512 x 512 spatial light modulator capable of modifying the phase or amplitude of the light passing though each array element. Photo courtesy of JPL.

Spatial Light Modulator (SLM) technology was significantly advanced by Boulder Nonlinear Systems under a NASA SBIR contract managed at Jet Propulsion Laboratory, opening the door to future NASA applications in spacecraft rendezvous and landing, and creating several exciting new commercial applications.

A spatial light modulator is a liquid crystal array capable of displaying images or serving as a tunable optical light filter. The 512 x 512 array developed by Boulder Nonlinear Systems is smaller than a dime and can change images as fast as 1,000 frames per second.

The NASA application for SLMs is in optical correlators—devices that are used for locating targets such as a spacecraft for rendezvous and docking, or identifying unique geographical features for landing on a planet or asteroid. A Mars sample return mission is a promising opportunity for the NASA application of the technology. Optical correlators compare current digital camera images with previously captured target images to determine location. The significant reduction in size achieved in SLM technology has resulted in a similar reduction in size of optical correlators, making spacecraft applications practical. The high frame rate has meant that optical correlators greatly surpass digital or computer-based approaches in the speed of their calculation.

Boulder Nonlinear Systems’ SLMs have been integrated into several exciting new commercial products. One manufacturer has purchased them for their light tweezers. Light tweezers use laser beams focused through a microscope to move particles as small as individual molecules. At the microscopic level, the use of light beams makes it possible to move small particles within living cells without the danger of contamination associated with more invasive approaches. SLMs are used to tailor the laser beams to significantly enhance the capabilities of light tweezers.

Another promising commercial opportunity exists in searching visual records for matches. Comparing a known visual pattern such as a fingerprint to an unknown visual pattern requires very high-speed processing. Optical correlators using SLM technology are opening new opportunities in this field because of the speed at which they can make comparisons.

Other commercial opportunities exist in holography, optical information processing, image processing, neural networks, optical memory, biometric recognition, security systems and anti-counterfeiting. Early applications in these fields have contributed to the commercial success of this product. Q

For more information, contact Byron Jackson at Jet Propulsion Laboratory SBIR Program Office at 818/354-1246. Please mention you read about it in Innovation.

NASA Official: Jonathan Root • Web Design: Printing & Design Office, NASA Headquarters • Credits