| 摘要 |
PURPOSE:To obtain a high-power light source having a single-peak distribution of intensity at the center of curvature, by arranging a plurality of distributed feedback laser resonators provided with a grid consisting of concentric arcs so as to orient the resonators toward the center of curvature of the grid. CONSTITUTION:An N-type InP buffer layer 2 is deposited on an N-type InP substrate 1. A thin film of resist is provided and a grid consisting of concentric arcs with a radius of curvature of 2mm is drawn by an electronic beam at a cycle of 2,000Angstrom . After development, the substrate is etched to form a concentric arc grid 3 having a depth of about 500Angstrom . An N-type InGaAsP waveguide layer 4, an active layer 5, a P-type InP clad layer 6 and P<+> type InGaAsP cap layer 7 are overlaid thereon so as to have predetermined energy gaps and thicknesses, respectively. This multilayer structure is subjected to photolithography and etching to form radial mesa stripes such that the center of the radial pattern coincide with the center of curvature of the grid. The mesa stripes are covered with P- and N-type InP 8. After a preselected electrode is provided, a sector-shaped mesa pattern is produced by photolithography and etching. When resonators are excited simultaneously, a single-peak output corresponding to approximately the total of all the resonators appears at the position where beams are converged. This is an effect convenient in practical use. |
