One-Joule-Per-Pulse Q-switched 2-micron solid state laser

Q-switched output of 1.1 J per pulse at 2-micron wavelength has been achieved in a diode pumped Ho:Tm:LuLF laser using a side-pumped rod configuration in a Master-Oscillator-Power-Amplifier (MOPA) architecture. This is the first time that a 2-micron laser has broken the Joule per pulse barrier for Q-switched operation. The total system efficiency reaches 5% and 6.2% for single and double pulse operation, respectively. The system produces excellent 1.4 times of transform limited beam quality. OCIS codes: (140.3580) Laser, solid state; (140.3480) Lasers, diode-pumped Two-micron, pulsed, coherent-detection lidar systems provide carbon dioxide vertical profiles and tropospheric wind profiles with high measurement precision. The key component in these lidar systems is a reliable, high energy and efficient 2-micron laser. The laser has to be injection seeded and frequency controlled to meet the single frequency requirement for these measurements as well. For a space-borne coherent lidar system, joule level output energy is required to be able to accurately measure the global wind fields. Although theoretical simulation predicted that Ho and Tm based lasers would have generated Joule energy decades ago, not such a high energy laser has been reported. Recently, significant advancements in the 2-micron laser development have been made in terms of high energy demonstrations. A 125 mJ injection seeded 2-micron Ho:Tm:YLF oscillator at room temperature was developed in 1998. A 400mJ Qswitched 2-micron laser system using a conductively cooled laser pump module was reported in 2004. A 600 mJ Q-switched diode-pumped Tm:Ho:LuLF using a MOPA system at double pulse format was published in 2003. Last year, a Joule level 2-micron laser MOPA system was reported, but it was operated in double-pulse format. This paper describes, for the first time, a one-joule-per-pulse Q-switched 2-micron laser system, which makes a significant milestone in the high energy 2-micron laser development. The MOPA 2-micron laser system comprises an oscillator, a preamplifier and two power amplifiers as show in Figure 1. The MOPA system is a typical way to achieve high energy, and at the same time to preserve good beam quality required by the nature of coherent lidars. The laser and amplifiers are all designed in side-pumped rod https://ntrs.nasa.gov/search.jsp?R=20080015396 2017-11-06T23:32:09+00:00Z