VCSELs with a novel integrated quantum-well absorber

摘要

The high reflectivity of VCSEL mirrors renders the device very sensitive to small changes int he reflectivity or absorption within the laser cavity. Therefore, the integration of a quantum-well absorber within the VCSEL enables compact, monolithic devices with multiple functions. As a result, the VCSEL exhibits a variety of useful characteristics under different configurations. In this work, we demonstrate the use of a quantum-well absorber within one of the VCSEL mirror stacks. With strategic design and simple biasing circuitry, we have shown experimentally (1) a VCSEL with an integrated quantum-well photodetector, (2) a self-pulsating VCSEL with a controllable quantum-well saturable absorber, and (3) a novel technique for VCSEL modulation where the quantum-well absorption is modulated, thereby modulating the laser light output. The theory, design criteria, experimental results, and potential applications for these devices are discussed.