TRANSVERSE-MODE CONTROL OF VERTICAL-CAVITY SURFACE-EMITTING LASERS

Transverse-mode control of vertical-cavity surface-emitting lasers (VC SEL's) has been investigated. A theoretical model takes into account t he distributions of carriers, optical field, and temperature. Using a method of finding self-consistent solutions for the carrier diffusion, optical field, and thermal conduction equations, we have studied the influence of current spreading, injected current density, gain-guided aperture, and window diameter on the transverse modes. The calculated results agree well with those of experiments and show that the transve rse-mode evolution of VCSEL's depends on the changes of gain and refra ctive index induced by carriers and heating; decreasing temperature ri se and profile width, current spreading, and gain-guided aperture dime nsion, increasing homogeneity of the injected carriers at the lasing r egion, and decreasing window diameter are effective methods to suppres s high-order transverse modes.