High-contrast, high-brightness ultraviolet laser system

Reflectivity and spectral shift from laser plasmas generated by high-contrast, high-intensity KrF laser pulses

“…After the first pass in the first amplifier, the pulse is sent through a pre-imaging system, comprised of a two lens telescope and a conventional spatial filter. After the second pass, the nonlinear Fourier filter was integrated into the system [28]. The laser arrangement is illustrated in figure 1.…”

Large Spectral Shift of Reflected Radiation From Laser Plasmas Generated by High Contrast KrF Laser Pulses

“…The laser system is based on a hybrid dye-excimer system [16]. The 500 fs long and 497 nm central wavelength output of a XeCl pumped distributed feedback dye laser is frequency doubled and amplified in a three tube, 6 pass KrF amplifier chain [15]. The pulse is sent through a so-called pre-imaging system which after the first pass consists of a two lens telescope and a conventional spatial filter.…”

“…It is to be noted that without the Fourier-filter the temporal contrast of the laser intensity dropped drastically to ∼5.5 × 10 5 . A modification of the arrangement of the present work as compared with Gilicze et al [15] is that the interferometric multiplexing was removed from the final amplifier in order to keep the polarization vertical or horizontal, which was selected in front of the amplifiers by a half-wave-plate. This, however, reduced the output energy to ∼80 mJ.…”

“…However later it was shown [5] that a UV prepulse of low (i.e., ∼10 7 Wcm −2 ) intensity may result in photoablation and photoionization, thus preformed plasma in the interaction range. New developments of pulse cleaning based on the Fourier-filtering technique [7] and its integration into our laser system [15] allowed us to achieve 10 12 temporal contrast against the ASE prepulse of the KrF system. Detailed studies of the reflectivity and investigations of the spectral shape are then carried out on high-Z (Au) and low-Z (B) targets with the KrF laser system offering 700 fs ontarget pulse duration and 1.15 × 10 18 Wcm −2 intensity.…”

Nagy intenzitású ultraibolya lézerekkel keltett plazmák kontrasztfüggő abszorpciója és dinamikája

“…Gilicze és munkatársai az erősítőlánc bővítésén felül sikeresen implementáltak egy új kontrasztjavító eljárást, az ún. nemlineáris Fourier-szűrőt [7]. Ez a rendszerben az első pátmenet utáni előleképezésből és a második átmenetet követő maszkolással ill. gázjetben való fókuszálással valósul meg (1.a ábra).…”