'From Quantum Cascade Lasers to Flat Optics'
Professor Federico Capasso, Harvard University
The ZI was priviledged to welcome Professor Federico Capasso, inventor of the quantum cascade laser and Robert Wallace Professor of Applied Physics as the speaker for its inaugural lecture.
Abstract
Our research on Quantum Cascade Lasers has led us to introduce new methods for beam shaping and wavefront engineering, including multi-wavelength beaming. These developments have in turn been the springboard for research on a new class of metasurfaces for wavefront engineering. Such metasurfaces, which for constant in plane phase gradients lead to generalized laws of reflection and refraction, consist of arrays of optical antennas that introduce phase discontinuities in the optical path. New lenses free of spherical aberrations, axicons, background free broadband quarter wave plates and spiral phase plates that create optical vortices are among the flat components we have demonstrated. The ultimate vision is to develop a new class of fast (nanosecond scale) spatial light wave modulators, phased arrays from the visible to the THz and fast beam steerable semiconductor lasers.
Short biography
Professor Capasso pioneered band gap engineering of semiconductor heterostructures, he invented the first quantum cascade laser and recently performed the first measurement of the repulsive Casimir force. He and his group invented a new class of plasmonic devices such as plasmonic laser antennas and discovered powerful generalisations of the laws of reflection and refraction applicable to metasurfaces, which they used to design and demonstrate a new class of flat optical components ranging from aberration free lenses to novel vortex plates. Read Professor Federico Capasso's full profile.