Free electron micro-lasers

The electron optical properties of microscopic gated field emitter arrays (FEA) are an ideal match to the electron beam requirements of free electron micro-lasers. Projected performance characteristics of the beam generators based on the FEA principle are reviewed and results from recent experiments with a single micro-beam filament are summarized. The latter are shown to support the claim that free electron micro-lasers based on either the Cherenkov or the Smith-Purcell interaction mechanism are a practical possibility.