DISTORTED QUANTUM WELL SEMICONDUCTOR LASER ELEMENT

PURPOSE:To narrow a half value of total angle of a far field pattern of a lateral mode in an active layer in a vertical direction and to form an optical beam to be oscillated in a circular shape by providing a light confinement layer made of InGaAsP between the active layer and a clad layer. CONSTITUTION:In a semiconductor laser element 109, a buffer layer 102 made of n-type GaAs of 0.5mum thick, a clad layer 103 made of n-type InGaP of 1.0mum thick, a light confinement layer and an optical waveguide layer 104, a distorted quantum well active layer 105 made of InGaAs of 110Angstrom thick, a light confinement layer and an optical waveguide layer 106, a clad layer 107 made of p-type InGaP of 1.5mum thick, and a contact layer 108 made of p-type GaAs of 0.5mum thick are sequentially laminated on an n-type GaAs semiconductor substrate 101. References 201, 201' denote light confinement layers made of InGaAsP of 0.03mum thick, and two layers are, for example, provided. Number 202 denotes an optical waveguide layer made of GaAs of 0.03mum adjacent to the layer 105.