Design and performance of a vertical cavity surface emitting laser based on III-V quaternary semiconductor alloys for operation at 1.55 mu m

A highly efficient Vertical Cavity Surface Emitting Laser (VCSEL) has been designed and fabricated for operation at a wavelength of 1.546 mum. The dev ice design incorporates optimized Bragg mirrors with minimized number of pe riods. The present structure employs quaternary III-V semiconductor alloys with GaInAsP as the active layer and AlGaInAs/InP multilayer stack as the D istributed Bragg Reflector (DBR). The material parameters of the quaternary alloys including index of refraction and bandgap energy are calculated ove r the entire composition range. The difference in the indices of refraction between AlGaInAs and InP alternating layers is found to be 0.46 resulting in a significant reduction of the number of DBR layers. The MBE technique i s employed for the epitaxial VCSEL structure growth and the selective oxida tion of AlInAsP single layer is used to form the current confinement apertu re. The VCSEL gain performance has been calculated and measured, resulting in the experimental threshold current of about 3 mA and the output power of 1 mW.