The　degradation　of　broad-area　AlGaAs/GaAs　laser　diodes　is　studied　experimentally　and　theoretically　in　detail,　and　we　suggest　a　degradation　mechanism　associated　with　the　stress　which　originates　from　the　lateral　spatial　hole　burning　(SHB)　effects.　Our　analysis　shows　that　thermal　stresses　have　critical　effects　on　the　degradation　of　laser　diodes,　which　are　induced　by　increased　local　heating　by　nonradiative　recombination　and　self-absorption　of　photons　originating　from　the　lateral　SHB　within　the　laser　diode　during　degradation.　Such　results　are　confirmed　by　the　simulation　using　the　software　LASTIP.　Furthermore,　the　average　values　of　the　induced　thermal　strain　and　stress　by　lateral　SHB　are　0.00063　and　85　MPa,　respectively,　through　the　x-ray　diffraction　measurement.　The　stress　exceeds　that　for　the　initiation　of　plastic　deformation　(as　calculated　to　be　approximately　40-50　MPa　based　on　the　finite　element　method),　thus,　suggesting　that　plastic　deformation　has　occurred　within　the　cavity　due　to　the　lateral　SHB　effect　during　degradation　of　laser　diodes.　(C)　2012　American　Institute　of　Physics.　[http://dx.doi.org/10.1063/1.4768194]