Optical properties of individual Al0.2Ga0.8As/Al0.4Ga0.6As multiple quantum well microdisks in large periodic arrays are investigated by micro-photoluminescence spectroscopy at room temperature. We can produce arrays where the shape of the individual disks ranges from circular over quadratic to laterally coupled structures. For circular disks we observe several whispering gallery modes over a broad range of energy. The shape of the disk strongly affects the linewidths of the optical modes; deviations from the circular shape lead to lower quality factors. We can experimentally discriminate between the transverse electric and transverse magnetic modes by collecting the emitted light from the side of a disk.