LAUSR

Abstract This paper presents a laser diode (LD) end-pumped square-rod Nd:glass laser system capable of achieving joule-level output energy at 1-Hz repetition rate. The laser system generated 966 mJ of energy in a 5-ns pulse for a pumping energy of 9.66 J at 802 nm, corresponding to an optical-to-optical conversion efficiency of 10%, which is higher than those of similar existing systems. A single-pass small-signal gain of 2.54 and pulse energy stabilities of 2.5% (peak-valley) and 0.37% (root-mean-square) were achieved by eight-pass amplification. The output energy of 966 mJ was generated, and the near-field modulation of 90% beam aperture was 1.37; further, the 82.5% far-field energy concentration was 2.5 times higher than the diffraction limit. The measured single-pass thermally induced wavefront aberration (1.15 λ ) was similar to that calculated using the thermal model. The beam quality could be further improved using adaptive phase corrector technology.