Tracking FS Lasers

High-speed Free Space Optical (FSO) Communications Beam Trackers

High-speed free-space optical (FSO) laser communications have been used increasingly for short- and long-distance ground-to-ground transmissions, ground-to-air, air-to-air, ground-to-space and inter-spacecraft links. Optical wireless free space communications involving moving parties, especially at extra-long distances, require precise beam pointing and mutual tracking of communicating transceivers in order to maintain Gbps optical links. Short wave infrared (SWIR) cameras, based on InGaAs detector technology, image the YAG and "eye-safe" laser wavelengths (1.06 and 1.5 µm) typically used for free-space communications.

The diagram below shows how a space-to-ground-to-air FSO free space communications system would require precise alignment of the transceiver laser beams.

Sensors Unlimited offers high-frame rate cameras specifically for locating the laser source while full-frame imaging. This permits the control electronics to quickly slew the FSO system to center the beam in the image. The camera can then be switched to image just the center portion at high-speed to keep the high-speed detector centered in the laser beam despite rapid movements of both the transmitter and receiver platforms. These cameras can also be used in adaptive optics systems for increasing link distance in the free space communication by correcting for atmospheric distortions and attenuation. These windowing camera models from Sensors Unlimited, SU320KTSW and SU640SDWH, can serve your FSO needs.

Many SWIR camera capabilities are considered sensitive. If you would like to learn more about SWIR capabilities for the military, you can register at a special web site, You must be a US Government employee or a USG contractor and be a US Citizen to access this site.