A monolithic vertical cavity bistable device based on the InGaAlAs system has been grown by low pressure metalorganic vapor phase epitaxy in a single run. First observation of all-optical bistability is reported in this new monolithic structure, with a contrast of 15:1 and a threshold power of less than 300 &mgr;W. X-ray diffraction and reflectivity measurements confirmed the high crystallographic and optical qualities of the material. This result shows that the InGaAlAs system is well suited to the fabrication of vertical cavity devices in the optical communication wavelength range. ©1997 American Institute of Physics.