Semiconductor lasers with 2-D-photonic crystal mirrors based on a wet-oxidized Al2O3-mask

We have fabricated and investigated AlGaAs-InGaAs-based ridge waveguide (RWG) lasers with two-dimensional (2-D) triangular photonic crystal (PC) mirrors using a wet-oxidized Al/sub 2/O/sub 3/ mask for the dry etching of the PC at one end of the ridge. The laser structure includes a 60-nm-thick AlAs layer positioned in the upper cladding, which is converted into Al/sub 2/O/sub 3/ after the definition of the PC by electron beam lithography and shallow etching. Etching of the holes is then continued using the Al/sub 2/O/sub 3/ mask, to a final depth of 600 nm. The continuous-wave characteristics of the lasers show a clear dependence on the period of the PC including a significant decrease of the threshold current and an increase of the efficiency for properly adjusted crystal parameters.