A blue-violet semiconductor laser device has a first p-electrode formed on its upper surface and a first n-electrode formed on its lower surface. A red semiconductor laser device has a second n-electrode formed on its upper surface and a second p-electrode formed on its lower surface. An infrared semiconductor laser device has a third n-electrode formed on its upper surface and a third p-electrode formed on its lower surface. Solder films are partially formed on the upper surface of the first p-electrode in the blue-violet semiconductor laser device. Two of the solder films are formed with a predetermined distance between them on the upper surface of the first p-electrode. This results in a portion of the first p-electrode being exposed. The first, second and third p-electrodes of the blue-violet semiconductor laser device, red semiconductor laser device, and infrared semiconductor laser device are common electrodes.