OPTICAL SEMICONDUCTOR DEVICE

PURPOSE:To prevent welding spatters at the welding of a can so as to obtain an element excellent in reliability by a method wherein a ring-like groove where a flange of the can is fitted is formed at the position on a primary face of a package where the can is welded. CONSTITUTION:A can 10 is welded to a primary face of a package 8 through the intermediary of a flange 14 of the can 10 covering a laser diode chip 1. Here, as a groove 9, whose width is a little larger than that of the flange 14 of the can 10, is provided to the primary face of the package 8 surrounding the center of the package 8 in a ring, welding spatters occurring at the welding of the can 10 can be absorbed by the groove 9. By these processes, welding spatters can be prevented at the welding of a can, so that an optical semiconductor device excellent in reliability can be obtained.