Atmospheric Propagation Testing With A High Power, Tunable Thulium Fiber Laser System

Abstract

A tunable master oscillator power amplifier (MOPA) fiber laser system based on thulium doped silica fiber designed for investigation of multi-kilometer propagation through atmospheric transmission windows existing from ∼2030 nm to ∼2050 nm and from ∼2080 nm to beyond 2100 nm is demonstrated. The system includes a master oscillator tunable over \u3e200 nm of bandwidth from 1902 nm to beyond 2106 nm producing up to 10 W of linearly polarized, stable, narrow linewidth output power with near diffraction limited beam quality. Output from the seed laser is amplified in a power amplifier stage designed for operation at up to 200 W CW over a tuning range from 1927 - 2097 nm. Initial field tests of this system at the Innovative Science & Technology Experimental Facility (ISTEF) laser range on Cape Canaveral Air Force Station, Florida will be discussed. Results presented will include investigation of transmission versus wavelength both in and out of atmospheric windows, at a variety of distances. Investigations of beam quality degradation at ranges up to 1 km at a variety of wavelengths both in and out of atmospheric transmission windows will be also presented. Available theoretical models of atmospheric transmission are compared to the experimental results. © 2010 Copyright SPIE - The International Society for Optical Engineering