Quest for the Smallest Possible Laser

How small a laser can be practically realized? – it is not a curiosity question any more in view of perceived future requirements of all-optical signal processing in communications, quantum computing. This is the question asked at the forefront of the photonics research. In this talk, the search for the smallest possible laser over the last three decades will be reviewed. The evolution of resonant cavities from the 1-D vertical cavity surface emitting laser to the 2-D photonic crystal laser and back to the 1-D ladder-type nano-beam laser will be discussed with biased historical perspectives. Detailed emphases will be placed on recent 1-D nanobeam lasers.