High-Order Harmonics Generation in Selenium-Containing Plasmas

The studies of the high-order harmonics generated in Se-containing plasmas are reported. ablation selenium a vacuum allowed for formation plasma demonstrating generation and resonance enhancement harmonic at shortest wavelength reported so far (λ ≈ 22.9 nm, Eph 54.14 eV). This corresponds to 35th order 800-nm-class lasers. influence presence molecular state (ZnSe HgSe) on suppression effect during is studied. enhanced was analyzed by different methods using nanosecond, picosecond, femtosecond pulses. factor resonance-enhanced measured be 32× compared with neighboring lower-order case picosecond-pulses-induced Se plasma. role strong ionic transition region 22.7 nm observation resonance-induced single discussed.