Capasso Group's Optical Harmonic Combs Could Operate as THz Source

Researchers at Harvard's John A. Paulson School of Engineering and Applied Sciences (SEAS) have discovered a new phenomenon of quantum cascade laser frequency combs, which would allow the devices to act as integrated transmitters or receivers that can efficiently encode information. Members of the Capasso Group have shown that a laser can act as a quadrature modulator, allowing two different pieces of information to be sent simultaneously through a single frequency channel and retrieved at the other end of a communication link. The new phenomenon has a technological significance for efficient use of bandwidth in communication systems. Professor Federico Capasso explains his group's discovery.