Wavelength and intensity switching in directly coupled semiconductor microdisk lasers

We demonstrate output wavelength and intensity switching in a three-element directly coupled microdisk device consisting of one spiral microdisk coupled to two semicircle microdisks. The gapless coupling mechanism used allows individual elements to achieve lasing while achieving optimal transfer of optical power between adjacent microdisks. By controlling the transparency of the center element via injection current, the edge elements can be allowed to exchange their amplified spontaneous emission. In this manner, on-off-on switching of the output intensity, as well as discontinuous shifts in the output wavelength, can be achieved as a function of increasing injection current.