High Power Optical Amplifier (HPOAs) for Free Space

ABSTRACT: Kigre proposes to develop and integrate unique radiation hardened, athermal, 1.5um laser gain materials and pumping architectures into high performance optical laser amplifier devices for SATCOM applications. The approach employs long life radiation tolerant pump diodes configured for direct side pumping of large mode area laser glass gain elements. Traditional single mode fiber laser amplifier designs are limited in terms of pump power, stability, noise, gain and power. Direct side pumping circumvents traditional laser amplifier issues with simpler, smaller and more scaleable architectures. They may be made into radiation hardened high power laser devices that provide reliable, rugged, temperature insensitive solutions for stable, low noise operation. Erbium glass gain materials are identified as ideal for use in laser amplifiers designed for satellite communications. This high gain laser glass provides numerous property advantages such as high gain, low heat fraction, high cross section, broad bandwidth, high solubility for rear-earth ions, insensitivity to concentration quenching, low upconversion losses, ability to self-compensate for induced strain/lensing due thermal loading, high energy storage and stable high gain laser amplifier performance in relatively short (compact) gain lengths. BENEFIT: Compact high efficiency radiation resistant HESP laser amplifiers would have potential commercial applications in free-space ground and satellite communications. Other commercial applications may include laser radar, collision avoidance, laser plasma spectroscopy, laser ignition and medicine. Military markets include satellite communications, LAser Detection And Ranging (LADAR), LIght Detection And Ranging (LIDAR), tracking, atmospheric sensing, targeting, illumination Additional applications include directed energy, long range eye-safe laser terrain mapping and laser designation.