ABSTRACT
We have developed a 157-nm coherent light source by two-photon resonant four-wave mixing in Xe, with two tunable single-mode 1-kHz Ti:sapphire laser systems at 768 and 681 nm. This light source has been developed to determine the instrumental function of a vacuum ultraviolet spectrometer and to evaluate optical designs for ultra-line-narrowed F(2) laser lithography. The spectral linewidth of the source was less than 0.008 pm (FWHM), with an average power of 0.6 mW.
ABSTRACT
We have developed a 50-W average-power KrF excimer laser with a pulse width of 480 fs by using the method of gated gain amplification at a 200-Hz repetition rate.
ABSTRACT
We have developed an all-solid-state 5-kHz Ti:sapphire laser system, which produces 22-fs, 0.2-TW pulses. An average power of 22.2 W is the highest ever obtained in ultrashort laser sources. The serious thermal lensing due to high power pumping in a small area of the Ti:sapphire crystal is controlled successfully by a stable quasi-cavity with two concave mirrors.
ABSTRACT
Autocorrelation measurement was demonstrated for the first time to our knowledge in the XUV region to measure the width of a high-order harmonic pulse. Two-photon ionization of rare gases was used as a nonlinear process for the autocorrelation measurement. The 27-fs pulse width that was obtained is, to our knowledge, the shortest in the XUV region.
ABSTRACT
A 1-kHz, 0.66-TW Ti:sapphire laser has been developed. We obtained 21-fs, 14-mJ pulses with an extraction efficiency of 32% in the final amplifier. The dispersion through the system was successfully compensated for by insertion of a pair of prisms in a regenerative amplifier. The pulses were characterized by frequency-resolved optical gating and were in good agreement with dispersion calculated by three-dimensional ray tracing.
ABSTRACT
High-power sub-100-fs UV pulses were generated from a KrF excimer laser by spectral control and chirped-pulse amplification. The spectral width was broadened to 1.6 nm, resulting in 72-fs, nearly transform-limited pulses. The average output powers at 1 kHz were 0.6 and 1.2 W for pulse widths of 72 and 110 fs, respectively.
ABSTRACT
We measured the ultrashort XUV pulse width by the pump-probe method, using femtosecond dynamics of field ionization. We measured the pulse width of the ninth harmonic (88.3 nm) of a Ti:sapphire laser, using the difference of the absorption cross section between Kr and Kr(+). The change of transmission of the ninth harmonic for the delay between the pump and the probe pulses gives both the pulse width of the ninth harmonic and the recombination time of Kr(+). The measured pulse width of the ninth harmonic was 260 fs. The recombination time of Kr(+) was ~2 ps, which does not contradict the estimated time of the threebody recombination.
ABSTRACT
We have developed a 1-kHz KrF/Ti:sapphire hybrid laser system. Average power was 7 W at 248 nm with a pulse width of 300 fs. A kilohertz Ti:sapphire regenerative amplifier at a wavelength of 745 nm is also described.
ABSTRACT
Steady-state chirped-pulse amplification was applied to a five-stage dye amplifier system to extract available energy over the full gain duration and at the same time suppress the amplified spontaneous emission (ASE). An output energy of 41 mJ was generated with 1.4-ns chirped pulses having an ASE of 3% and a pumping efficiency of 8.8% for the final amplifier. After five-stage amplification these pulses were compressed to 320 fs FWHM.
ABSTRACT
A terawatt KrF/Ti:sapphire hybrid laser system with a high contrast between amplified spontaneous emission and the main pulses has been developed with an output energy of 130 mJ in 130-fs pulses. An efficient frequencytripling scheme with Ti:sapphire is demonstrated with an efficiency of 11% in the 100-fs regime with LiB(3)O(5) and beta-BaB(2)O(4).
