Long-wavelength vertical-cavity surface-emitting lasers

In recent years vertical-cavity surface-emitting lasers (VCSELs) have aroused great interest amongst scientists and enterprises in China and abroad, as they have wide potential application in the optical communications field. We review the history, applications, device structures, materials and fabrication of long wavelength VCSELs. Current problems and possible solutions in their research and development are presented as well as their future prospects.