Line-Focus Generation for X-Ray Laser Pumping
Down-scaling of X-ray lasers towards shorter wavelengths imposes the need for higher irradiance of the pump laser systems. Typically, for a factor of 2 reduction in wavelength, a factor of ∼10 increase in irradiance was so far required. This discourages the use of refractive optics after the compressor stage of the high-power CPA laser systems commonly used for pumping X-ray lasers due to increasing nonlinear phase distortion (B-Integral). We present ray-tracing calculations of alternative focusing schemes applying reflective optics for grazing-incidence line-focus generation. The proposed mirrors deliver a narrow and shortened line focus from a high-aperture input beam, yielding an increase of irradiance on target.