Deep Saturated Free Electron Laser Oscillators and Frozen Spikes

TL;DR

This paper investigates deep saturated FEL oscillators, revealing stable sub-peaks called frozen spikes, their physical origins, and implications for harmonic generation and cavity out-coupling.

Contribution

It introduces the concept of frozen spikes in deep saturated FEL oscillators and explores their physical mechanisms and potential applications.

Findings

Identification of stable sub-peaks (frozen spikes) in deep saturated FELs

Analysis of their coherence length and stability

Discussion on their effects on harmonic generation and cavity out-coupling

Abstract

We analyze the behavior of Free Electron Laser (FEL) oscillators operating in the deep saturated regime and point out the formation of sub-peaks of the optical pulse. They are very stable configurations, having a width corresponding to a coherence length. We speculate on the physical mechanisms underlying their growth and attempt an identification with FEL mode locked structures associated with Super Modes. Their impact on the intra-cavity nonlinear harmonic generation is also discussed along with the possibility of exploiting them as cavity out-coupler.