The Optical-Antenna LED, Faster than the LASER

Antennas emerged at the dawn of radio for concentrating electromagnetic energy into a volume much smaller than the wavelength cubed, allowing for nonlinear radio detection. Conversely, an antenna can efficiently extract radiation from a sub-wavelength source, such as a small cellphone.

Over 100 years after the radio antenna, we finally have tiny “optical antennas” which can extract radiation from molecules, quantum dots, or Light Emitting Diodes, (LED’s). Optical antenna LED’s can be faster than Lasers, but the LED speedup is limited by optical losses through the “anomalous skin effect”, among other loss mechanisms. Nonetheless, 50% efficiency and a 10x speedup beyond stimulated emission should be possible for on-chip optical communication.