nLight proposes the development of high efficiency, high average power 1550-nm laser transmitter system that is based on Er-doped fiber amplifier resonantly pumped by high efficiency 1532-nm fiber-coupled diode laser pumps. To meet the efficiency requirement for space communication, nLight proposes to improve overall laser transmitter efficiency by (1) optimizing diode laser and fiber coupling for maximum efficiency of 1532-nm pumps, (2) developing resonant pumping of the fiber amplifier for minimum quantum defect, and (3) design and development of Er-doped fiber amplifier capable of achieving high optical-to-optical efficiency. Under the proposed program, nLight will design and develop high efficiency 1532-nm diode lasers in conjunction with highly efficient fiber coupling techniques to achieve >40% conversion efficiency of the pump modules. By developing and utilizing novel fiber laser amplifier technologies, nLight anticipates achieving > 70% optical-to-optical efficiency for resonantly pumped Er-doped fiber amplifier. It is estimated that a high efficiency 1550-nm fiber laser transmitter will be developed to demonstrate >23 W average power and >23% WPE, the highest efficiency among eye-safe solid-state lasers.
Potential NASA Commercial Applications: (Limit 1500 characters, approximately 150 words) A potential NASA application of the proposed eye-safe high efficiency, high average power fiber amplifier lies in space-based optical telecommunication. Fiber-based master oscillator power amplifiers at 1550 nm are believed to be the most likely candidates for laser transmitters that meet the efficiency, power and modulation requirement of deep-space optical communication. In addition to data communication, such laser transceiver system can provide precision range and velocity tracking for spacecraft navigation. The proposed system can also be used in direct energy detection Light Detection and Ranging (LIDAR) systems for atmospheric research and meteorology. Narrow linewidth pulsed laser systems operating around 1.6 um would be particularly applicable for direct detection differential absorption LIDAR CO2 measurements.
Potential NON-NASA Commercial Applications: (Limit 1500 characters, approximately 150 words) Commercial applications of this type of laser system may be in materials processing where the eye-safe wavelength and high peak power capability of the fibers developed may provide an advantage in terms of application speed or quality. If such systems are found to be useful for industrial applications, nLight will pursue commercialization of such products as an addition to their existing line of 1 um commercial pulsed fiber laser products. For instance, there is substantial interest in 15xx to 19xx nm lasers for a variety of plastics welding and biomedical applications. It is expected that these high average power, high pulse energy eye-safe fiber lasers will be useful in materials processing, biomedical, and other light industrial applications. There is also an emerging market in eye-safe Flash-LIDAR/LADAR for both military and industrial sensing applications which require both the pumps and the fiber laser/amplifiers proposed in this program.
Technology Taxonomy Mapping: (NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.) Emitters Lasers (Communication) Lasers (Ladar/Lidar)
