The present invention is to provide a vertical cavity surface emitting
laser diode (VCSEL) that has a functional distributed Bragg reflector
(DBR) comprised of less number of pairs of reflective layers. The VCSEL
of the invention include a lower DBR, an upper DBR and an active layer
arranged between the upper and lower DBRs. The upper DBR is comprised of
a plurality of pairs including GaAs layers and aluminum oxide layers,
thus the GaAs layers and the aluminum oxide layers are alternately
stacked to each other. Since the refractive index of the aluminum oxide
(Al.sub.2O.sub.3) is 1.67 at 1.3 .mu.m and that of the GaAs is 3.51, the
difference of these refractive index becomes 1.85, which is far greater
than the combination of the AlAs and the GaAs, thereby decreasing the
number of pairs for the DBR.