Electromagnetically induced waveguiding in double-Λ systems

This study discusses electromagnetically induced waveguiding in double-λ systems. The waveguiding effect is shown to be strongly phase dependent, indicating that it derives from the phase-dependent effective third-order susceptibility rather than the phase-independent effective first-order susceptibility, as is the case in previously studied systems. This work also shows that when the second Λ system initially involves only a single laser beam, the loop is completed by the efficient generation of radiation at the four-wave mixing frequency, within a propagation distance much shorter than the diffraction length.