A semiconductor laser includes a first optical confinement layer, a plurality of first quantum wires and buried semiconductor regions disposed on a first area, a plurality of second quantum wires and buried semiconductor regions disposed on a second area, an active layer disposed on a third area, and a second optical confinement layer. The plurality of first quantum wires and the buried semiconductor regions constitute a first distributed Bragg reflector, and the plurality of second quantum wires and the buried semiconductor regions constitute a second distributed Bragg reflector. The third area is disposed between the first area and the second area. The buried semiconductor regions have a refractive index different from the average refractive index of the first quantum wires and the average refractive index of the second quantum wires. These distributed Bragg reflectors form a DBR laser having a cavity length defined by the length of the active layer.