SEMICONDUCTOR LASER

PURPOSE:To contrive to reduce the value of threshold current and unify the transverse mode by restraining the transverse directional expansion of drive current by providing current stricture layers which form narrow current passage on the side of an N type semiconductor layer and that of a P type semiconductor layer which sandwich an active layer. CONSTITUTION:The current passage 9 of the stripe width W composed of a P type inversed region wherein zinc is selectively diffused is formed in an N-GaAs layer 5. Since the P-N junction part between a P-A GaAs layer 2 and the layer 5 becomes into reverse bias when a forward directional voltage is impressed on electrodes 7 and 8, holes injected from the hole injection electrode 8 pass only the current passage 9 and then flow into the active layer 3. The current passage 11 is formed by forming P type inversed regions 10a and 10b wherein zinc is diffused in the electrode layer 6 and the N-A GaAs layer 4 on both sides. Potential barriers due to the P-N junction are formed on both sides of the current passage 11, and while electrons injected from the electron injection electrode 7 flow into the active layer 3 by forming the stripe width W. A light emitting region 12 of the width equal to the stripe width W is formed in the active layer 3, therefore the unification of the transverse mode can be contrived.