Vieira J, Trines R M G M, Alves E P, Fonseca R A, Mendonça J T, Bingham R, Norreys P, Silva L O
GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.
Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot, OX11 0QX, United Kingdom.
Phys Rev Lett. 2016 Dec 23;117(26):265001. doi: 10.1103/PhysRevLett.117.265001. Epub 2016 Dec 20.
We identify and explore a high orbital angular momentum (OAM) harmonics generation and amplification mechanism that manipulates the OAM independently of any other laser property, by preserving the initial laser wavelength, through stimulated Raman backscattering in a plasma. The high OAM harmonics spectra can extend at least up to the limiting value imposed by the paraxial approximation. We show with theory and particle-in-cell simulations that the orders of the OAM harmonics can be tuned according to a selection rule that depends on the initial OAM of the interacting waves. We illustrate the high OAM harmonics generation in a plasma using several examples including the generation of prime OAM harmonics. The process can also be realized in any nonlinear optical Kerr media supporting three-wave interactions.
我们识别并探索了一种高轨道角动量（OAM）谐波产生与放大机制，该机制通过在等离子体中进行受激拉曼背散射，在保持初始激光波长的情况下，独立于任何其他激光特性来操控OAM。高OAM谐波光谱至少可以扩展到傍轴近似所施加的极限值。我们通过理论和粒子模拟表明，OAM谐波的阶数可以根据一个取决于相互作用波初始OAM的选择规则进行调谐。我们通过几个例子展示了等离子体中高OAM谐波的产生，包括素数OAM谐波的产生。该过程也可以在任何支持三波相互作用的非线性光学克尔介质中实现。
