Thermal　characteristics　including　the　temperature,　the　heat　flux,　and　the　temperature　gradient　of　GaAs-based　semiconductor　disk　lasers　(SDLs)　under　various　conditions　are　modeled　using　the　finite　element　method.　The　effects　of　the　substrate　thickness,　the　pump　spot　radius,　the　heatspreader,　and　the　pump　power　on　the　thermal　properties　of　laser　are　simulated,　and　the　maximum　temperature　rise　in　active　region　is　highlighted.　Numerical　analysis　predicts　that　SiC　is　an　ideal　substitute　for　diamond　as　a　heatspreader.　Instead　of　the　sophisticated　completely-etched　substrate,　the　use　of　a　high-thermal-conductivity　heatspreader　along　with　partly-etched　substrate　can　provide　sufficient　thermal　management　to　the　laser.　(C)　2011　Elsevier　GmbH.　All　rights　reserved.