Thermal　properties　of　the　distributed　Bragg　reflector　(DBR)　used　in　the　semiconductor　gain　element　are　crucial　for　the　performance　of　a　semiconductor　disk　laser　(SDL).　For　the　purpose　of　more　reasonable　semiconductor　wafer　design,　so　as　to　improve　the　thermal　management　of　SDLs,　accurate　thermal　conductivity　value　of　a　DBR　is　under　considerable　requirement.　By　the　use　of　equilibrium　molecular　dynamics　method,　thermal　conductivities　of　GaAs/AlAs　DBRs,　which　are　widely　employed　in　1　pm　waveband　SDLs,　are　calculated,　and　simulated　results　are　compared　with　the　reported　experimental　data.　Influences　of　the　layer　thickness　on　the　thermal　conductivities　of　the　DBR　structure　and　the　effects　of　Al　composition　on　the　AlxGa1-xAs　ternary　alloy　values　are　focused　and　analyzed.　(C)　2017　Elsevier　Ltd.　All　rights　reserved.