Nonlinear focusing of Terahertz laser beam using layered superconductor

Abstract

We theoretically study the propagation of a Terahertz (THz) Gaussian beam through a thin sample of layered superconductor. We consider the beam axis and the superconducting layers to be perpendicular to the sample interface, while the electric field in the beam is perpendicular to the layers. We show that, in such a geometry, the Josephson current between the superconducting layers supports lensing of the beam instead of divergence on the Rayleigh range. Moreover, due to the nonlinearity, the focal length and waist of the transmitted beam depend on the incident beam intensity. These dependences demonstrate nontrivial hysteresis behavior that can be observed in experiments with THz lasers.

References in corpus (4)

• Thermoelectrically cooled THz quantum cascade laser operating up to 210 K
• Probing quasiparticle dynamics in Bi2Sr2CaCu2O(8+delta) with a driven Josephson vortex lattice
• Restoring Interlayer Josephson Coupling in La_{1.885}Ba_{0.115}CuO_4 by Charge Transfer Melting of Stripe Order
• Oblique surface Josephson plasma waves in layered superconductors