LASER CHIP AND PREPARATION METHOD THEREFOR

Disclosed in the present invention are a laser chip and a preparation method therefor. Said method comprises: providing a laser epitaxial structure, the laser epitaxial structure comprising an active layer, and a cladding layer and a contact layer which are sequentially stacked on the active layer; covering a first mask layer on the contact layer, and a photolithograph step is performed on the first mask layer to form a first window region; performing primary etching on the contact layer by means of the first window region, so as to form a second window region corresponding to the first window region and exposing the cladding layer; performing zinc diffusion on the cladding layer and the active layer by means of the first window region and the second window region; removing the first mask layer; covering a second mask layer on the contact layer, and a photolithograph step is performed on the second mask layer to form a third window region, the projection of the third window region on the contact layer being located at the periphery of the second window region; and performing secondary etching on the contact layer by means of the third window region, so as to enlarge the second window region to correspond to the third window region. The described method can effectively increase a catastrophic optical mirror damage threshold.