Federico Capasso (born 1949) is an Italian-American applied physicist and is one of the inventors of the quantum cascade laser during his work at Bell Laboratories.
He applied it to novel low noise quantum well avalanche photodiodes, heterojunction transistors, memory devices and lasers.
Capasso's current research in quantum electronics deals with very high power continuous-wave QCLs, the design of new light sources based on giant optical nonlinearities in quantum wells such as widely tunable sources of terahertz radiation based on difference frequency generation and with plasmonics.
He used the Casimir effect (the attraction between metal surfaces in vacuum due to its zero point energy) to control the motion of MicroElectroMechanical Systems (MEMS).
In 2005 he received, jointly with Nobel Laureates Frank Wilczek (MIT) and Anton Zeilinger (University of Vienna), the King Faisal International Prize for Science for his research on quantum cascade lasers.
In 2016 he was awarded the Balzan Prize for Applied Photonics "For his pioneering work in the quantum design of new materials with specific electronic and optical features, which led to the realization of a fundamentally new class of laser, the Quantum Cascade Laser; for his major contributions in plasmonics and metamaterials at the forefront of photonics science and technology".
He received the Matteucci Medal in 2019 from the Italian National Academy of Sciences for his invention of the quantum cascade laser.