Gamma-ray vortices emitted from nonlinear inverse Thomson scattering of a two-wavelength laser beam
Gamma-ray vortices emitted from nonlinear inverse Thomson scattering of a two-wavelength laser beam
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DOI：
10.1103/physreva.98.052130
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发表时间：
2018-11
影响因子：
2.9
通讯作者：
Y. Taira;M. Katoh
中科院分区：
文献类型：
--
作者：
Y. Taira;M. Katoh
We develop a classical theory of nonlinear inverse Thomson scattering of a two-wavelength laser beam, which is valid for laser beams with linear or circular polarization and arbitrary intensity and wavelength. We reveal that an electron inside a circularly polarized two-wavelength laser field undergoes a cycloid motion in the transverse plane and radiates an electromagnetic wave forming a spiral phase structure. Its photon energy is proportional to a linear combination of the product between the initial laser photon energies $\ensuremath{\hbar}{\ensuremath{\omega}}_{01}$ and $\ensuremath{\hbar}{\ensuremath{\omega}}_{02}$, and their harmonic numbers ${n}_{1}$ and ${n}_{2}$, namely, ${n}_{1}\ensuremath{\hbar}{\ensuremath{\omega}}_{01}+{n}_{2}\ensuremath{\hbar}{\ensuremath{\omega}}_{02}$. The orbital angular momentum of a photon due to the spiral phase structure is given by $({n}_{1}+{n}_{2}\ifmmode\pm\else\textpm\fi{}1)\ensuremath{\hbar}$. We show that a combination of two wavelengths differing by one order of magnitude or more is advantageous for producing gamma rays carrying a large orbital angular momentum of $\ensuremath{\sim}10\ensuremath{\hbar}$. Moreover, this work indicates that a helical undulator with two magnetic periods is capable of producing photons with a large orbital angular momentum. This radiation process plays an important role in the development of optical vortex beams and even in astrophysical environments.
We develop a classical theory of nonlinear inverse Thomson scattering of a two-wavelength laser beam, which is valid for laser beams with linear or circular polarization and arbitrary intensity and wavelength. We reveal that an electron inside a circularly polarized two-wavelength laser field undergoes a cycloid motion in the transverse plane and radiates an electromagnetic wave forming a spiral phase structure. Its photon energy is proportional to a linear combination of the product between the initial laser photon energies $\ensuremath{\hbar}{\ensuremath{\omega}}_{01}$ and $\ensuremath{\hbar}{\ensuremath{\omega}}_{02}$, and their harmonic numbers ${n}_{1}$ and ${n}_{2}$, namely, ${n}_{1}\ensuremath{\hbar}{\ensuremath{\omega}}_{01}+{n}_{2}\ensuremath{\hbar}{\ensuremath{\omega}}_{02}$. The orbital angular momentum of a photon due to the spiral phase structure is given by $({n}_{1}+{n}_{2}\ifmmode\pm\else\textpm\fi{}1)\ensuremath{\hbar}$. We show that a combination of two wavelengths differing by one order of magnitude or more is advantageous for producing gamma rays carrying a large orbital angular momentum of $\ensuremath{\sim}10\ensuremath{\hbar}$. Moreover, this work indicates that a helical undulator with two magnetic periods is capable of producing photons with a large orbital angular momentum. This radiation process plays an important role in the development of optical vortex beams and even in astrophysical environments.