Juan C. Gallardo

Binomial states of the quantized radiation field: comment

Following a recent suggestion that binomial states exist in the quantized radiation field [ D. Stoles B. E. A. Saleh M. Teich , Opt. Acta32, 345 ( 1985)], we discuss a simple physical model that leads to binomial probability distribution. We also point out the relation between the binomial states and the generalized SU2 coherent states.

Cylindrical Gaussian-Hermite modes in rectangular waveguide resonators

Approximate solutions to the wave equation inside a rectangular metallic waveguide has been obtained in terms of cylindrical Gaussian-Hermite functions.Emnπ modes propagate with negligible straight guide losses in the far-infrared region. A new type of low-loss optical resonator suitable for FEL operation at long wavelengths is presented here.

Multimode dynamics in a free electron laser with energy shift

A one-dimensional, multimode self-consistent phenomenological theory for a free-electron laser (FEL) oscillator is investigated numerically. The fundamental equations of an FEL are supplemented with a discontinuous decrease of the electron beam energy at each successive round trip in the cavity. The laser power exhibits oscillations produced by the growth and decay of longitudinal modes evenly distributed in frequency. The model underlines the basic mechanism operating in the University of California, Santa Barbara free-electron laser.

Photon statistical properties of an optical-wiggler free-electron laser

We use the free-electron laser Hamiltonian to study the statistical properties of the photons emitted in a scattering process between a coherent electromagnetic wave (optical wiggler) and a counterpropagating relativistic electron beam. It is shown that the probability distribution of exchanged photons is binomial and that coherent states are preserved by the free-electron-laser interaction only in the absence of gain.

Far‐infrared, low‐loss, cylindrical‐Gaussian eigenmodes of a bent rectangular waveguide free electron laser resonator

This reprint presents approximate analytical solutions of the Helmhotz equation for a slightly bent metallic rectangular waveguide with infinite aperture cylindrical mirrors. The low-order, overmoded, low-losses eigenmodes of the cold resonator are naturally expressed as products of cylindrical Gaussian-Hermite and trigonometric functions. In first order in perturbation theory, the correction to the attenuation constant. Modes propagate with negligible losses in the far-infrared region. These results are compatible with preliminary experimental data from the Free Electron Laser experiment.

Quantum statistical properties of an FEL amplifier

We discuss the problem of photon quantum statistics of a single particle free-electron laser (FEL) amplifier in the small-signal cold beam regime to first order in the electron quantum recoil. The initial radiation wave is an arbitrary coherent state. We show that Glauber coherence is not preserved by the FEL interaction if the initial coherent state is not the vacuum, even if we neglect the electron quantum recoil (absence of gain). We evaluate the first two moments of the final photon distribution and find sub- (super)-Poissonian photon statistics for a negative (positive) resonance parameter.

Small-signal gain of Free Electron Laser in a resonator Gaussian mode

We present an analytical expression for the small-signal gain of a Free Electron Laser (FEL) in the presence of a Gaussian mode. To describe the electron beam evolution we use the one-dimensional (1-d) Vlasov equation. Our perturbation result, valid for small values of the parameterq (length of the undulatorL divided by the Rayleigh rangeZR), can be extrapolated to values ofq≈4÷5.

Multimode free electron laser with long electron pulses: effects of electron energy drift

Abstract We discuss a phenomenological one dimensional, self-consistent, multimode (longitudinal) theory for a free electron laser oscillator. A strong fundamental mode and two weak side-band modes are followed through many passes in the optical cavity as the energy of the electron beam decreases monotonically. The time evolution of the laser power exhibits oscillations produced by the sequential growth to saturation and subsequent decay of longitudinal modes evenly distributed in frequency.

The spherical Raman-Nath equation with time-dependent coefficients

SummaryIn this paper we write the exact solution of the Spherical Raman-Nath equation with time-dependent coefficients in terms of a hypergeometric function. Finally we indicate how already known results can be derived from this more general expression.

Incoherent emission of an electron beam in a free electron laser rectangular waveguide

A calculation is presented of the incoherent radiation emitted by an electron beam of finite radius passing through a linearly polarized magnetic undulator in a rectangular waveguide with perfect conducting walls. This analysis is based on the Fourier component of the Lienard-Wiechert fields. The metallic boundary conditions are exactly incorporated in the formalism by means of the image currents method. In the Fresnel approximation, we show that the double infinite sum over images is transformed into one over vertical modes, consisting of trigonometric functions. The discreet frequency spectrum and angular distribution of the radiation are studied.