JPS57145385A - Method for generating light pulse train - Google Patents

Abstract

PURPOSE:To obtain the light pulse train whose light intensity is modulated, by providing a concave part in a part of a resonator comprising laminated semiconductors whose opposing ends become the Fabry-P erot reflecting surfaces, respectively, thereby dividing an exciting region into two parts, and applying bias currents having the different threshold current values or the values in the vicinity thereof to the respective regions. CONSTITUTION:A laminated body 35 comprising a P type semiconductor substrate 31, a P type semiconductor confining layer 32, an N or P type semiconductor active layer 33, and an N type semiconductor confining layer 34 is formed. The opposing end surfaces are used as the Fabry-P erot reflecting surfaces 36 and 37, and double heterogeneous type semiconductor laser device is obtained. In this constitution, an electrode 38 is deposited on the side of the substrate 31, and the electrode 39 is deposited on the side of the confining layer 34. At this time, the concave part 40 is provided at the end part of the substrate 31, thereby dividing the electrode 38 into 41 and 42 and also dividing the exciting region into M1 and M2. Thereafter, a bias power source 45 is connected to the electrode 41 through a choke coil 43, and a bias power source 46 is connected to the electrode 42 through a choke coil 44. The electrode 39 is grounded.