A broad area semiconductor laser device is provided having an NFP with top hat shaped profiles for the P wave and the S wave, which result from polarized beam splitting of the emitted light. The broad area semiconductor laser device of the present invention has the same structure as the broad area semiconductor laser device of the prior art, except that the composition of an etch stop layer is different. The semiconductor laser device includes an n-Al_0.5Ga_0.5As first clad layer, an active layer including an AlGaAs optical guide layer and an AlGaAs quantum well layer, a 0.3 m thick p-Al_0.5G_0.5As lower second clad layer, an Al_0.7Ga_0.3As etch stop layer, a p-Al_0.5Ga_0.5As upper second clad layer, and a p-GaAs contact layer, which form a laminated structure on top of an n-GaAs substrate.