PURPOSE: To provide an optical device having more allowance for wire bonding by employing a structure, wherein each electrode includes a wide part and a narrow part extending from the wide part and having a wire bonding area, and the electrodes are arranged laterally in such a manner that the wide parts are adjacent to the narrow parts.
CONSTITUTION: An optical device 1 includes a plurality of electrodes 10, and one surface of each electrode has a wire bonding area 22. The electrode 10 includes a wide electrode part 19 and a narrow electrode part 20 extending from the former part. The bonding area 22 is located on the wide part 19. These electrodes are arranged laterally in such a manner that the wide parts are adjacent to the narrow parts. For example, a semiconductor laser device 1 capable of emitting four beams includes a p-type GaAs substrate 2 on which a multilayer 7 is grown. The multilayer is divided into four regions by crank- shaped isolation grooves 4, each region including a semiconductor laser 3.