Making Light Coherent

Alexander A. Lisyansky, E. S. Andrianov, Alexey P. Vinogradov +1 more

X. Y. Zou, L.J. Wang, Timothy P. Grayson +1 more

A new technique for varying the degree of coherence between two light beams through the amplitude of a third beam, without affecting the light intensities, is described. The method makes use of the process of parametric down-conversion in two similar non-linear crystals which are coherently pumped with their idlers aligned, and it allows very precise variation of the degree of coherence.

Oliver S. Heavens

J.-P. Goedgebuer, Jean-Marc Mérolla

Coherence modulation of light consists in coding a signal as an optical delay greater than the coherence length of light. It makes use of interferometers powered by sources which exhibit a short coherence length. Such sources can be operated either as classical sources or quantum sources. We describe some applications dealing with optical communications and quantum cryptography.

Dilawar Ali, Muhammad Umer Iftikhar, Muqaddar Abbas +1 more

Abstract A cold atomic medium (Rydberg medium) with cascade configuration under the blockade mechanism is considered. A partial coherent light (PCL) beam is incident on the medium, which makes an angle θ with z-axis. We study the influence of PCL field on the transmission spectrum and find high transmission of probe field for PCL field. Conversely, it is investigated that the transparency of probe field decrease for coherent light field. The transmission of probe field is also studied via beam width of PCL field and investigated high transmission of probe field for small beam width and vice versa. Interestingly, the Goos-Hänchen shift (GHS) in the transmitted light (TL) is studied for PCL field. Large negative and positive GHS in the TL are investigated for PCL field and small beam width of PCL field.