Various embodiments of the present invention are related to microresonator systems that can be used as a laser, a modulator, and a photodetector and to methods for fabricating the microresonator systems. In one embodiment, a microdisk comprises: a top layer; a bottom layer; an intermediate layer having at least one quantum well, the intermediate layer sandwiched between the top layer and the bottom layer; a peripheral annular region including at least a portion of the top, intermediate, and bottom layers; and a current isolation region configured to occupy at least a portion of a central region of the microdisk including at least a portion of the top, intermediate, and bottom layers and having relatively lower index of refraction than the peripheral annular region.