Xenon plasma sustained by pulse-periodic laser radiation

The possibility of sustaining a quasi-stationary pulse-periodic optical discharge (POD) in xenon at a pressure of p = 10–20 bar in a focused 1.07-μm Yb³⁺ laser beam with a pulse repetition rate of f_rep ⩾ 2 kHz, pulse duration of τ ⩾ 200 μs, and power of P = 200–300 W has been demonstrated. In the plasma development phase, the POD pulse brightness is generally several times higher than the stationary brightness of a continuous optical discharge at the same laser power, which indicates a higher plasma temperature in the POD regime. Upon termination of the laser pulse, plasma recombines and is then reinitiated in the next pulse. The initial absorption of laser radiation in successive POD pulses is provided by 5p⁵6s excited states of xenon atoms. This kind of discharge can be applied in plasma-based high-brightness broadband light sources.