Abstract
We developed an optical system that transforms a one-dimensional emission pattern of a 1-cm LD-bar into a two-dimensional spot size suitable of longitudinally pumping a solid-state laser with an excellent mode coupling efficiency. The LD-bar beams are collimated by a rod lens and a lens array in the direction perpendicular and transverse to the diode junction plane, respectively. A multiple reflection beam shaper is placed after the lens array to rearrange the entire beam profile from the linear to almost square. An aspheric condenser lens then produces a focused spot of _??_390μm x 220μm. We applied this shaped diode laser beam to pump a Nd: S-VAP laser. The optical distortion induced with thermal loading increases diffraction loss in the cavity. Significant decrease of the output laser power was observed as increasing the thermal load, together with the distortion in the output beam pattern.
