Effect of Losses on the Gain and Start Current in Smith-purcell Free-electron Lasers
نویسندگان
چکیده
[email protected] Abstract The effect of dissipative losses in the grating surface of a Smith-Purcell free-electron laser is examined analytically. It is shown that losses have a significant impact on the gain of amplifiers (which operate on a convective instability) and on the growth rate of oscillators (which operate on an absolute instability), but it is not absolutely necessary for the ideal gain (without losses) to exceed the ideal attenuation (without gain) to have positive net gain or growth rate.
منابع مشابه
Numerical Simulation of Smith-purcell Free Electron Lasers
We present a one-dimensional time-dependent analysis and simulation of Smith-Purcell (SP) free-electron lasers (FELs). The coupled Maxwell-Lorentz equations are set up, and the details of numerical simulation are presented. At low electron beam energy, a SP-FEL is a backward wave oscillator (BWO), and oscillations can be achieved without the need for feedback mirrors. In the linear regime, we s...
متن کاملCollective and Single-Electron Interactions of Electron Beams with Electromagnetic Waves, and Free-Electron Lasers*
The field of radiation emission from electron beams is reviewed with special reference to work related to free-electron lasers. Different schemes o f interaction in periodic structures, electromagnetic slow-wave structures, and in transverse confining force are distinguished. Various effects and devices such as traveling wave amplifiers, Smith-Purcell radiators, Cerenkov and bremsstrahlung-free...
متن کاملModulation Response and Relative Intensity Noise Spectra in Quantum Cascade Lasers
Static properties, relatively intensity noise and intensity modulation response in quantum cascade lasers (QCLs) studied theoretically in this paper. The present rate equations model consists of three equations for the electrons density in the conduction band and one equation for photons density in cavity length. Two equations were derived to calculate the noise and modulation response. Calcula...
متن کاملThe dispersion equation of the induced Smith-Purcell instability
The simplest model of the magnetized infinitely thin electron beam is considered. For the grating, which has depth of grooves as a small parameter, the dispersion equation of the induced Smith-Purcell instability was obtained. It was found that the condition of the Thompson or the Raman regimes of excitation does not depend on beam current but depends on the height of the beam above grating sur...
متن کاملAnalysis of Kirk Effect in Nanoscale Quantum Well Heterojunction Bipolar Transistor Laser
In this paper, we present an analytical model to analysis the kirk effect onstatic and dynamic responses of quantum well heterojunction bipolar transistor lasers(HBTLs). Our analysis is based on solving the kirk current equation, continuityequation and rate equations of HBTL. We compare the performance (current gain,output photon number and small signal modulation bandwi...
متن کامل