Operational wavelength range for low insertion loss and high extinction ratio of GaInAs(P)-InP intersectional optical switches consisting of low-dimensional quantum-well structures, such as quantum-box, quantum-wire, and quantum-film structures, is theoretically analyzed. As a result, it is found that superior operation characteristics can be attained with the lower dimensional quantum-well structure, for instance, operational wavelength range of around 10 nm for insertion loss less than 1 dB and extinction ratio higher than 50 dB can be obtained with the device using a quantum-box structure.