Vertical cavity etalons with asymmetric superlattice claddings have been fabricated. As predicted earlier, the cavities with sawtooth superlattice claddings grown on (100) oriented substrate are birefringent with the new optical axes along (011) and (01¯1) directions. The difference in the resonant wavelengths of the cavity modes polarized along (011) and (01¯1) are measured to be about +0.3 and −0.3 A˚ for the two senses of our sawtooth superlattice structures. The change of the sign of the wavelength shift indicates that the observation is not due to an electro‐optic effect of the incorporatedp‐njunction but is due to the reduction of the III‐V crystalline symmetry by the presence of the asymmetric superlattice. ©1995 American Institute of Physics.