外部共振器型面発光半導体レーザー一光励起半導体レーザー一

摘要

Recent activities and progress on the development of vertical external cavity surface emitting lasers (VECSELs) or optically pumped semiconductor lasers (OPSLs) are reviewed. By engineering the bandgap, VECSELs/OPSLs can be made to operate at tailored wavelengths, giving access to broad spectral regions, extending from visible (red) to infrared, that were previously unavailable with solid -state laser materials. With the free space resonator configuration, intracavity frequency doubling allows efficient harmonic generation, further extending the wavelength to the shorter end. Nonlinear frequency conversion gives complete coverage of visible region and extends into the ultraviolet portion of the spectrum. Since the optical intensity of an OPSL device can be kept low by having large cross section of the resonator modes,this gives opportunities for high power operation. The potential of VECSELs/ OPSLs is explored toward the high power devices. Some of the scaling attempts are reviewed along with the design keys and relevant issues.