Cesium vapor laser with transverse pumping by multiple laser diode arrays

Theoretical analysis of the semi-ring and trapezoid LD side-pumped alkali vapor lasers

“…Pumped configurations have played an important role in enhancing the laser power of DPALs. Up to now, numerous experimental studies on DPALs with different pumped configurations were performed, including single-end pumped configuration [1,3,4,8], double-end pumped configuration [2,7], single-side pumped configuration with stable resonator [5] and unstable resonator [6]. Their corresponding models were set up by [9][10][11][12][13][14][15] and agreed well with the experimental results.…”

“…Diode-pumped alkali vapor lasers (DPALs), one of the lasers which are thought to have the potential to achieve high efficiency and high power in a high quality beam, have developed very fast during the past dozen years [1][2][3][4][5][6]. Especially since 2010, it has stepped into fluid age and reached $ kW level [7,8].…”

“…For the end-pumped configuration, it is very complicated and difficult to combine more than four pump beams into the vapor cell [23], thus employing the side-pumped configuration is a certain option. In the early work, the first sidepumped Cs laser with stable resonator has been demonstrated [5] and, then, upgraded with unstable resonator [6]. However, it seemed that coupling the pump beams of fifteen LDAs (laser diode arrays) inside the cell through a slit on the side had led to a mismatched mode overlap between lasing mode and pumped volume in the gain medium.…”

Review of alkali laser research and development

“…The efficiencies achieved in this experiment are more than twice higher than in our previous experiment utilizing transversely pumped Cs laser with a stable resonator . 48 We attribute to this increase in performance to the better overlap between lasing mode and pumped volume of the gain medium when using the unstable cavity geometry. However, the slope efficiency of this system is still lower than that for longitudinal pumping (81% for Ti:sapphire pump 40 and 68% for diode laser pump).…”

“…the same authors performed a series of scaling experiments with longitudinal 46,47 and transverse 48,49 pumping using multiple LDAs and both stable and unstable 49,50 configurations of the laser cavity. This allowed for an increase of the demonstrated output power of these alkali lasers to a level of tens of Watts.…”