Novel Approaches to Semiconductor Lasers

摘要

Modern trends in design of semiconductor lasers are reviewed. In one novel design, light propagates at some angle with respect to multilayer interference mirrors (MIRs), and the MIRs and the cavity are optimized for the tilted photon propagation. "Tilted cavity" laser (TCL) gives wavelength-stabilized operation in edge and (or) in surface direction and does not require materials having large difference in refractive indices. In a different concept, a high-order mode filtering in structures with periodically modulated refractive index containing a "defect" allows realization of a stable narrow beam divergence fundamental mode lasing in both edge-emitters and vertical-cavity surface-emitting lasers (VCSELs). Using of electrooptical modulators based on quantum confined Stark effect in VCSELs and TCLs allows a significant wavelength tuning range, ultrahigh-speed operation and direct wavelength adjustment to resonant cavity photodiode (RCPD) or tunable RCPD. Different types of tunable semiconductor optical amplifiers, switches, filers may become possible. New generations of cost-effective intelligent telecom systems with direct, ultrafast and wavelength adjustable connection between consumer devices and the storage or processing cites may be realized.