摘要
Micro-lens arrays were adopted to homogenize the beam profile of 532-nm pumping laser for the main amplifier of an intense femtosecond, chirped pulse amplification （CPA） Ti：sapphire laser. Experimental measurements showed a great improvement of the near-field pattern of the CPA beam after the main amplifier and the size of the focal spot was improved from 2.7 times diffraction limitation （DL） to 1.6 DL. The spot size focused by an f/4 off-axis parabola （OAP） in the target chamber was measured to be 5.8 pm （full-width at half-maximum （FWHM））, and a peak intensity of 2.6 × 10^20 W/cm^2 was obtained at the output power of 120 TW. Peak intensity exceeding 10^21 W/cm^2 or even 10^22 W/cm^2 can be expected with smaller f-number focusing configuration and wavefront correction.
Micro-lens arrays were adopted to homogenize the beam profile of 532-nm pumping laser for the main amplifier of an intense femtosecond, chirped pulse amplification （CPA） Ti：sapphire laser. Experimental measurements showed a great improvement of the near-field pattern of the CPA beam after the main amplifier and the size of the focal spot was improved from 2.7 times diffraction limitation （DL） to 1.6 DL. The spot size focused by an f/4 off-axis parabola （OAP） in the target chamber was measured to be 5.8 pm （full-width at half-maximum （FWHM））, and a peak intensity of 2.6 × 10^20 W/cm^2 was obtained at the output power of 120 TW. Peak intensity exceeding 10^21 W/cm^2 or even 10^22 W/cm^2 can be expected with smaller f-number focusing configuration and wavefront correction.
