ANALYSIS AND DESIGN OF VERTICAL-CAVITY SURFACE-EMITTING LASERS FOR SELF-SUSTAINED PULSATION OPERATION

The generation mechanism of self-sustained pulsation in vertical-cavit y surface-emitting lasers (VCSEL's) is analyzed with the influence of lateral loss effects, such as self-focusing, lateral diffraction loss, and spatial hole burning, taken into consideration, The condition for self-sustained pulsation is also derived in an analytical form, It is shown that the lateral loss effects have significant influence on the excitation of self-sustained pulsation, especially for devices with s mall size, Furthermore, the possibility of using diffused quantum-well . (QW) structures in VCSEL's to enhance self-sustained pulsation is st udied, It is found that by using diffused QW structures, the range of core area to obtain self-sustained pulsation is increased, In addition , peak power and repetition frequency of the pulses can also be improv ed.