High-brightness stack arrays for DPSSL laser applications

Abstract

For DPSSL applications at low duty cycle (typically 15Ois/2O Hz), we have developed a new concept of 'High Brigthness' stacked arrays, which leads to power density of 10 kW/cm2, and to 40 kW/cm2 when directly coupled to a lensduct. . The high intensity is made possible thanks to a new proprietary stacking technology [1] that permits a stacking pitch of only 100 im : the principle is to directly stack the arrays without any heat spreaders other than the arrays themselves. When compared to standard commercial QCW stacked arrays, the benefits of using these high brightness laser diodes pumping sources are the following:-an important cost reduction related to a drastic simplification in the assembling process.-an improved pumping efficiency associated with an improved brightness ('a factor 4), consequence of a reduced pitch between linear bar arrays.High-efficiency, frequency-quadrupled, end-pumped 8 mJ, 12-ns-long UV pulses @ O.266im Nd:YAG laser has been developped using these High Brightness pump sources This air-cooled laser is an attractive alternative to the more conventional millijoules-range UV source.A compact high energy 300 mJ Q -Switched diode -pumped laser has been developped. Laser performances and integration level demonstration contribute to a preliminary laser design for future airbown laser applications.