Vertical-Cavity Surface-Emitting Lasers With Two Emission-Controllable Transverse Modes

We propose a vertical-cavity surface-emitting laser (VCSEL) with two transverse modes independently controlled by two contacts. By directly etching a trench in the p-doped distributed Bragg reflector, we form an air gap and two sub-mesas as waveguides above the oxide layer. Contacts are deposited on each sub-mesa. Emission control on two different spatial modes in a single VCSEL is achieved by changing the driving condition of one-contact or two-contact injection. Owing to this feature, the proposed VCSEL has a potential as a cost-effective source for optical communications using spatial-division multiplexing.