Enhancement of Photon Number Reflected by the Relativistic Flying Mirror

Abstract

Laser light reflection by a relativistically moving electron density modulation (flying mirror) in a wake wave generated in a plasma by a high intensity laser pulse is investigated experimentally. A counterpropagating laser pulse is reflected and upshifted in frequency with a multiplication factor of 37-66, corresponding to the extreme ultraviolet wavelength. The demonstrated flying mirror reflectivity (from 3 x 10(-6) to 2 x 10(-5), and from 1.3 x 10(-4) to 0.6 x 10(-3), for the photon number and pulse energy, respectively) is close to the theoretical estimate for the parameters of the experiment.

Ultra-Intense, High Spatio-Temporal Quality Petawatt-Class Laser System and Applications

“…Because of the relativistic motion of the RFM, the frequency of the reflected pulse is upshifted to  4 ph is the Lorentz factor associated with the RFM, ω s and τ s are the frequency and the pulse duration of the source pulse, respectively. After the proof-of-principle experiment [86], we conducted an improved experiment with head-on configuration using the J-KAREN laser system [87]. Here we describe the summary of the experiment.…”

High Power Laser Facilities at the Kansai Photon Science Institute

“…In addition, two laser beam experiments will be easily implemented because our large compressor can accept dual beams with a small diameter (~100 mm). In this case, gamma-ray generation through Compton scattering [7], coherent X-ray generation by relativistic flying mirrors [8,9], colliding electron generation [10,11], and other experiments can be conducted.…”

On the breaking of a plasma wave in a thermal plasma. II. Electromagnetic wave interaction with the breaking plasma wave

“…In the present paper we address the problem of the interaction of an electromagnetic wave with a nonlinear plasma wave which is of interest for the "photon accelerator" concept [14] and for the "relativistic flying mirror" paradigm [6][7][8][9][10][11]. We calculate the reflection coefficients of an electromagnetic wave at the singularities of the electron density in the most typical regimes of a strongly nonlinear wave breaking in thermal plasmas.…”

“…This results in a finite reflectivity of an electromagnetic wave interacting with nonlinear plasma waves. In particular, this is an important property because nonlinear Langmuir waves play a key role in the "relativistic flying mirror" concept [6][7][8][9][10][11]. In this concept, very high density electron shells are formed in the nonlinear wake wave generated by an ultrashort laser pulse propagating in an underdense plasma with a speed close to the speed of light in vacuum.…”