| 摘要 |
PURPOSE:To conduct oscillation at low threshold currents and a single longitudinal mode while acquiring a high output by forming a corrugated P-type buffer layer, the surface thereof is brought to proper pitches and depth, on a P-type InP substrate and shaping an internal current constriction layer and double hetero-junction structure. CONSTITUTION:A P-type GaInAsP layer as a buffer layer 33 is formed on a P-type InP substrate 31 by using a liquid-phase epitaxy method (an LPE method). The surface of an unnecessary section in the buffer layer 33 is etched to shape a wave form 33a having proper pitches and depth on the surface of the buffer layer. Semiconductor layers consisting of two layers constituted of layers such as an N-type InP layer 35 and a P-type InP layer 37 functioning as current constriction layers are formed on the buffer layer 33 in succession by employing the LPE method. A striped groove 39 is shaped through a normal method. Double hetero-junction structure composed of a P-type GaInAsP optical waveguide layer 41, a GaInAsP active layer 43 and a N-type InP clad layer 45 and an N-type GaInAsP cap layer 47 are formed on the buffer layer 33 and the P-type InP layer 37 exposed by the groove 39 in succession through the LPE method. Accordingly, an element, which oscillates at low threshold currents and a single longitudinal mode and from which a high output can be obtained, can be formed simply. |
