Photoionization lasers pumped by broadband soft-x-ray flux from laser-produced plasmas

Abstract

Large population inversions on transitions ranging in wavelength from 109 to 748 nm have been produced in six elements pumped by photoionization through inner-shell and/or multielectron (shakeup) processes with the broadband soft-x-ray flux from laser-produced plasmas. Gain coefficients ranging from 0.25 to 11.5 cm−1 have been measured in He, Ar, Zn, Cd, In, and Xe using the soft-x-ray flux produced by 25–300-mJ, 70-psec-, and 10-nsec-duration pulses from a 1.06-μm laser. Extension of this scheme to Na suggests that a 10-mW average-power laser can be produced at 37.2 nm at a 10-Hz repetition rate by photoionizing Na vapor with the soft-x-ray flux produced with a 1-J, 50-psec-duration pulse from a 1.06-μm laser.