Attenuation of 10.6-μm beams by electrically initiated laser driven plasmas

Measurements have been made of the attenuation of radiation of λ=10.6 μm by a plasma initiated by an electrical spark in air. The light transmission varied from <2% to ≳10% as the input laser energy ranged from 300 mJ to < 0.1 mJ. These results indicate that the spark-initiated plasma acted as a seed plasma for the laser. The trend of increasing attenuation with increasing incident laser energy is promising for use as an isolator in high-power laser systems.