Coherent Control with Nonclassical Light

 

 Light generated by down conversion process can be broadband just like a short pulse, yet it is not coherent. Still, the inherent correlations between the signal and idler waves offers new possibilities, some of which we have demonstrated in recent publications [1-4].

 

  

Two-photon absorption with down-converted light

 

When broad-band light is generated via down conversion of a narrow-band pump, it combines two seemingly incompatible properties: It performs two-photon absorption with the efficiency and temporal characteristics of a femtosecond pulse, but it is sensitive to the tuning of the wavelength of the pump as if it is a cw experiment. Above is the schematics of a TPA experiment in Rubidium.

Below are some of the experimental results. For details see ref (3) below.

 

 

 

 

  

 

SFG with entangled photons

Entangled photons often behave as a single particle. If they arrive as single pairs, they perform nonlinear interactions at a rate that is linear with their flux.. This result has never been observed in a clear way, because it is quite hard to perform nonlinear interactions at single-photon levels. To overcome this, we have generated a very high flux of entangled photons by very broad down conversion. Even though we had some 1012 photon pairs per second, we still had less than one pair per mode.  This enabled us to observe an extremely linear dependence of a nonlinear interaction – sum frequency generation – on the number of pairs. The SFG could also be controlled and shaped using frequency domain manipulations of the relative phases of the photons, just like shaping femotsecond pulses.

 

 

 

Publications

    1.  “Coherent Control with Broadband Squeezed Vacuum”, B. Dayan, A. Pe’er, A.A. Friesem and Y. Silberberg, arXiv: quant-ph 302038 Feb 2003. PDF
    2. “Optical code-division multiple access using broad band parametrically generated light”, A. Pe’er, B. Dayan, Y. Silberberg and A.A. Friesem , J. Lightwave Technol. 22, 1463 (2004). PDF
    3. “Two-photon absorption and coherent control with broadband down converted light”, B. Dayan, A. Peer, A.A. Friesem and Y. Silberberg, Phys. Rev. Lett. 93, 023005 (2004). PDF
    4. “Nonlinear Interactions with an Ultrahigh Flux of Broadband Entangled Photons”, B. Dayan, A. Pe’er, A.A. Friesem and Y. Silberberg, Phys. Rev. Lett. 94, 043602 (2005). PDF
    5. “Temporal Shaping of Entangled Photons”, A. Pe’er, B. Dayan, A.A. Friesem and Y. Silberberg, Phys. Rev. Lett. 94, 073601 (2005). PDF

 

 

 

Yaron Silberberg
Ultrafast Optics Group