GaAlAs/GaAs Vertical Cavity Surface Emitting Active Filter

Semiconductor laser amplifiers are of interest for direct light amplification as well as functional operation such as wavelength filtering and so on. An optical filter with narrow bandwidth and wavelength tuning is one of key devices for dense wavelength division multiplexing (WDM) trunk lines and networks. So far, laser diode active filters using Fabry-Perot cavity or DFB/DBR laser structures have been studied [1] – [4] . There are remaining problems in these devices, such as large polarization sensitivity due to those rectangular waveguide structure and difficult coupling to optical fibers.