Recent advances in semiconductor crystal growth and process techniques have made it possible to produce semiconductor wire and box structures on a mesoscopic scale (''''1Onm). The interference of electron waves in the mesoecopic structures bring about various phenomena which are interesting from the view points of solid-state physics as well M device application. This paper addresses the recent progress in research on the semiconductor rnesoscopic structures that is fabrication processes characterization and application to optical devices. The unique optical features of the mesoscopic structures are discussed in relation to the quantum coithnenient effects in one-dimensional quantum wires and zero-dimensional quantum boxes. The carrier confinement effects in the low-dimensional systems lead to new concepts for device physics which utilize nonlinear birefringence and coherent nonlinearity. The current status and the problems associated with the fabrication of these semiconductor low-dimensional structures are also discussed. I.