Photonic Free-Electron Lasers

Coherent Cherenkov radiation and laser oscillation in a photonic crystal

“…Here we demonstrate a very different and much more general approach to photonic crystal Bloch mode lasers where gain and coherent output radiation is provided by free electrons, without relying on any specific gain material. Thereby, the range of output wavelengths is not bound to pre-determined values but can be scaled over orders of magnitude via scaling the spatial period * p.j.m.vanderslot@utwente.nl of the photonic crystal [19]. The work that we present here gives the first complete description and proof of coherent emission from a photonic crystal-based freeelectron laser, by solving self-consistently the coupled Maxwell and Lorentz-Newton equations in three dimensions.…”

Fiber optic probe of free electron evanescent fields in the optical frequency range

“…Indeed, while the nanoscale range of low/medium energy electron evanescent fields has provided for the emergence of electron-induced radiation emission (EIRE) and electron energy loss (EELS) spectroscopy techniques for probing and mapping the photonic and plasmonic properties of nanostructures, 18,[21][22][23][24] it places constraints on the experimental geometry in such studies and on the utility of freeelectron pumping in applications such as nanoscale tunable light sourcing. [25][26][27] Here, we report on an experimental platform using a tapered optical fiber geometry ( Fig. 1) akin to those employed for sampling evanescent light fields in near-field optical microscopy, which enables the study of proximity interactions between free electrons and nanophotonic structures mediated by the aforementioned exponentially decaying field at optical frequencies.…”

Theory and design of microwave photonic free-electron lasers

“…These codes have been successfully applied in a huge variety of situations. Examples are found in astrophysics, particle acceleration and FELs [69,83,[142][143][144][145][146]. For FELs in particular, these codes allow the investigation of multidimensional effects and highly nonlinear phenomena, which is very complex using other techniques [144].…”

“…Implementing these steps not only in a single spatial dimension, but in three-dimensions, makes PIC methods very powerful tools. For example, three-dimensional PIC methods allow to compute the temporal evolution of the electromagnetic field, particle positions and velocities in a slow-wave FEL [69,83,144,145]. Specifically for the present work, it becomes possible, e.g., to compute the steady-state output power of pFELs or investigate mode competition in pFELs.…”

“…This way the total beam current through the photonic crystal can be easily made far larger than the maximum current in other slow-wave FELs. Hence, utilizing photonic crystals as the gain medium for a FEL should enable to provide an increased gain and thereby also a more powerful laser output [69].…”