DISTRIBUTION FEEDBACK TYPE SEMICONDUCTOR LASER

PURPOSE:To realize continuous oscillating operation under a room temperature by previously providing periodical uneveness on the InGaAsP 4-element layer and by allowing growth of the InP layer thereon. CONSTITUTION:The p-n junction 12 is provided on the n type InP substrate 1, the n type InGaAsP layer 2 is grown thereon and uneven layer 8 is formed thereon. Thereafter, the n type InP layer 10, InGaAsP light emitting layer, p type InP layer 4, n type InGaAsP layer 5 are provided. In such a structure, the layer 10 is grown on the uneven surface of the layer 2. Accordingly, the saturation degree of InP can be made considerably large and since the grating matching of InP can be obtained in the same composition for any orientation of plane, the good uneven surface can be formed. Thereby, an operating current is lowered and a considrably small threshold oscillation value can be obtained, thus making possible the continuous oscillating operation under a room temperature.