Low Power Consumption Laser for Undersea Communications

Period of Performance: 06/14/2002 - 06/14/2004

$743K

Phase 2 SBIR

Recipient Firm

Aculight Corp.
22121 - 20th Avenue SE
Bothell, WA 98021
Principal Investigator

Abstract

The Navy is faced with the problem of transmitting data between various platforms and underwater instrumentation. Security and safety prevent physical contact between the platform and the data source so remote optical communication is necessary. A frequency doubled Nd:YAG laser is used in these situations because it produces a green beam for efficient transmission through coastal waters. Unfortunately, these lasers are inefficient so they are relatively large and power hungry. Aculight offers unique semiconductor laser technology that requires only 5% of the electrical power of comparable Nd:YAG lasers and can be directly modulated and fiber coupled. The innovation enables the use of blue/green lasers in battery-powered instruments that must operate underwater for extended periods. We demonstrated electrical efficiencies of 30% in the Phase I program. This technology can yield lasers with optical powers ranging from 100 mW to over 100 Watts and wavelengths from ultraviolet to mid- infrared. In this program, we propose to build a compact laser that will produce a high quality red beam that can be upgraded to green when the diodes become available. The red laser, although merely a first step, has a detection distance that is only 20% shorter than a comparable DPSS laser.BENEFITS: The high brightness visible semiconductor laser we will develop has direct application as an illuminator for photodynamic therapy drugs. In some cases, the laser energy must to be delivered by a highly flexible catheter so the laser must have sufficient beam quality for efficiently coupling into a small diameter fiber optic. These lasers are also needed in high volume for large venue projection laser display systems.