Ultrahigh-brightness, femtosecond ArF excimer laser system

An ultrahigh-brightness ArF excimer laser system is described that is capable of generating pulse energies of 60 mJ with a pulse duration of ~700 fs. The system utilizes a newly developed seed pulse generation scheme based on spectrally compensated sum-frequency mixing in beta-barium metaborate (BBO), and a double-pass discharge pumped ArF excimer preamplifier followed by an electron beam pumped power amplifier

Femtosecond gain characteristics of the discharge-pumped ArF excimer amplifier

The gain characteristics of a discharge-pumped ArF excimer amplifier are measured with ~700-fs-long pulses. The small-signal gain and saturation energy are found to be 0.17 cm-1 and 3.65 ± 0.15 mJ/cm2, respectively. The maximum output energy density extracted from the deeply saturated amplifier is as much as 10 mJ/cm2. The demonstrated femtosecond gain characteristics of ArF indicate that, by utilizing sufficiently high seed pulse energies, the ArF excimer laser is expected to show a performance similar to a femtosecond high-brightness KrF excimer laser system

Generation of high-power subpicosecond pulses at 155 nm

Subpicosecond vacuum-ultraviolet radiation at 155 nm with pulse energies above 0.2 mJ has been obtained by near-resonant four-wave difference-frequency mixing in a Xe gas jet. Laser fields for the mixing process have been generated by a short-pulse KrF dye excimer laser system and a Raman converter. The process permits tuning in a broad vacuum-ultraviolet range and can be scaled up to higher output energies

Spectrally compensated sum-frequency mixing scheme for generation of broadband radiation at 193 nm

A dispersively compensated scheme for sum-frequency mixing of broadband ultrashort laser pulses is reported. An increase of the bandwidth of the sum-frequency mixing process by 12 times compared with the noncompensated bandwidth of the given crystal has been demonstrated. Mixing radiation at 266 and 707 nm in a 1-mm-thick beta-barium metaborate crystal by using the compensated scheme results in an output bandwidth of 0.6 nm at 193 nm, which corresponds to a minimum output pulse duration of 90 fs

Single-shot autocorrelator for KrF subpicosecond pulses based on two-photon fluorescence of cadmium vapor at X = 508 nm

By excitation of cadmium vapor with a high-peak-power KrF excimer laser pulse, fluorescence of an atomic transition at X = 508 nm is induced by a two-photon ionization process followed by fast recombination. The nonlinear response of the medium is used to develop a simple single-shot autocorrelator for subpicosecond KrF excimer laser pulses operating down to intensities of less than 109W/cm.2 We have measured 360-fs (FWHM) pulses at X = 248 nm with a time resolution of 15 fs

Infrared recombination lasers pumped by low energy Nd: YAG and excimer lasers

24 infrared laser lines on atomic and ionic transitions have been observed in recombining plasmas by vaporizing and ionizing Cd, Pb, Sn, Zn, and Mg with low energy Nd:YAG or excimer pump-lasers. For operation and optimization of the recombination lasers separated plasma spots and a plasma confinement have been used. The operation of shorter wavelength systems by isoelectronic scaling is discussed

Generation of short-pulse VUV and XUV radiation

Starting from intense short-pulse KrF (248 nm, 25 mJ, 400 fs), ArF (193 nm, 10 mJ, sim1 ps), and Ti:sapphire (810 nm, 100 mJ, 150 fs) laser systems, schemes for the generation of fixed-frequency and tunable VUV and XUV radiation by nonlinear optical techniques are investigated. With the KrF system, a four-wave mixing process in xenon yields tunable radiation in the range of 130–200 nm with output energies of, so far, 100 mgrJ in less than 1 ps. For the XUV spectral range below 100 nm, nonperturbative high-order harmonic generation and frequency mixing processes in noble gas jets are considered. To achieve tunability, the intense fixed-frequency pump laser radiation is mixed with less intense but broadly tunable radiation from short-pulse dye lasers or optical parametric generator-amplifier systems. In this way, tunability down to wavelengths of less than 40 nm has been demonstrated

Photon pressure induced test mass deformation in gravitational-wave detectors

A widely used assumption within the gravitational-wave community has so far been that a test mass acts like a rigid body for frequencies in the detection band, i.e. for frequencies far below the first internal resonance. In this article we demonstrate that localized forces, applied for example by a photon pressure actuator, can result in a non-negligible elastic deformation of the test masses. For a photon pressure actuator setup used in the gravitational wave detector GEO600 we measured that this effect modifies the standard response function by 10% at 1 kHz and about 100% at 2.5 kHz