A surface emitting semiconductor laser diode of a tunnel junction type
includes a semiconductor substrate, a first reflector, a second
reflector, an active region disposed in series between the first and
second reflectors, and a tunnel junction region disposed in series
between the first and second reflectors. The tunnel junction region
includes a first semiconductor layer of a first conductive type and a
second semiconductor layer of a second conductive type that forms a
junction with the first semiconductor layer, the first semiconductor
layer being composed of a supper-lattice layer that at least partially
includes aluminum and is partially oxidized.