A p-type pad electrode in a red semiconductor laser device and a first
terminal are connected through a wire. A p-type pad electrode in an
infrared semiconductor laser device and a second terminal are connected
through a wire. A p-electrode in a blue-violet semiconductor laser device
and a third terminal are connected through a wire. An n-electrode in the
blue-violet semiconductor laser device is electrically conducting to
amount. An n-electrode in the red semiconductor laser device and the
mount are connected through a wire, while an n-electrode in the infrared
semiconductor laser device and the mount is connected through a wire. The
mount has a fourth terminal inside.