A novel principle of active multi-mode-ingerferometer (MMI) bi-stable laser diode (BLD), utilizing differnt lateral modes, has been proposed and demonstrated for optical random access memory (RAM) application. The two different propagation modes realize two different identical paths in a single active MMI cavity simultaneously, with shering exactly same port at one facet side. This novel concept contributes to realize relatively large cross-gain saturation region between the two identical paths, which result in stable bi-stability even in a relatively compact device size. Implemented devices showed relatively low operation current of 100mA and sufficient hysteresis window of 8mA with the cavity length of only 550 micro meters. High optical ON/OFF ratio of more than 15dB was also confirmed successfully.
[ FULL TEXT (pdf) ]