Methods and Apparatus for Generating Coherent Light at New Frequencies via Floquet Lasing

A time varying laser which can operate by taking advantage of transitions between time varying quasi-energy levels which are present in the driven system is disclosed. This can allow for laser operation at frequencies which are new, compared to the operation of the laser in absence of time-modulation. It can also allow for a novel mode of operation in which the system provides gain at multiple frequencies simultaneously, in a coherent fashion which is fundamentally different from multi-mode behavior in conventional lasers. Additionally, in systems with sufficiently strong modulation, these principles can lead to lasers which produce gain even in the thermodynamic ground state of the system, leading to a new form of lasing without inversion (LWI). In addition, these techniques have the potential to be used to create lasers at high frequencies (UV-Xray) which have been difficult to achieve via conventional laser mechanisms.