Reconfigurable digital functionality of composite resonator vertical cavity lasers

The composite resonator vertical cavity surface laser can perform multiple digital functionalities at greater than 10 GHz bandwidth, including: direct intensity modulation, wavelength division multiplexing, multilevel pulse amplitude modulation, and optical picosecond pulse generation. The unique attributes of these microcavity lasers arise from the two strongly coupled optical cavities which can be electrically injected independently. Reconfiguration among multiple functionalities is achieved by control of the three terminal signals input into the laser and can be achieved using a high-speed digital circuit whose logic can be adjusted to provide appropriate modulation voltages to the optically coupled laser cavities. The novel optical properties of composite resonators are reviewed with a focus on several different digital functionalities possible from this semiconductor laser.