| 摘要 |
PURPOSE:To provide a longitudinal multimode in a wide-stripe range and reduce the noise by a method wherein the stripe width is large enough to cause a single transverse mode oscillation near, at least, one end face of a resonator but wider at other area than this end face. CONSTITUTION:A multilayer structure has a semiconductor substrate 1, an active layer 4 formed thereon, a pair of clad layers 3 and 5 sandwiching the layer 4, and current constricting layer 7 for injecting a current into a stripe-like region of the layer 4. At least one of the clad layers 3 and 5 has a stripe-like ridge extending in the direction of a resonator of a semiconductor layer, and its stripe width is large enough to cause a single transverse mode oscillation near, at least, one end face of the oscillator and wider at other area than the resonator. |
