We have investigated the optical properties of single disks comprising buried quantum wells fabricated byin situelectron-beam lithography by using a low-temperature microphotoluminescence method. Photoluminescence images of a disk array showed the distribution due to emissions from single disks with diameters down to 0.1 &mgr;m. In the photoluminescence and photoluminescence excitation spectra of single disks, the peak positions were almost constant irrespective of disk diameter. Moreover, the photoluminescence spectra had almost equal peak intensities when corrected for the disk diameter and the distribution width in the photoluminescence image. These optical properties indicate successful fabrication of buried quantum-well structures. ©1997 American Institute of Physics.