We present our experimental demonstration of controlling the cavity output intensity of one laser beam with the intensity of another laser beam in a composite system consisting of a collection of three-level ?-type rubidium atoms and an optical ring cavity. When the intensity of the controlling beam is modulated with a square waveform, the cavity output power switches on and off (with a distinc...

Terrestrial Free-space optical communication (FSO) links have yet to achieve a mass market success due to the ever elusive 99.999% availability requirement. The terrestrial FSO links are heavily affected by atmospheric fog. To design systems which can achieve high availability and reliability in the presence of fog, accurate and better models of fog attenuation need to be developed. The current...

Using the mean-field time-dependent Gross-Pitaevskii equation we study the formation of a repulsive Bose-Einstein condensate on a combined optical and harmonic traps in two and three dimensions and subsequent generation of the interference pattern upon the removal of the combined traps as in the experiment by Greiner et al. [Nature (London) 415, 39 (2002)]. For optical traps of moderate strengt...

All-optical photonic devices are crucial for many important photonic technologies and applications, ranging from optical communication to quantum information processing. Conventional design of all-optical devices is based on photon propagation and interference in real space, which may rely on large numbers of optical elements, and the requirement of precise control makes this approach challengi...

versity of Berlin for offering me a stimulating scientific environment and for their kindness. It was a real pleasure to work with them.

We establish the concept of the density of the optical degrees of freedom that may be applied to any photonics based system. As a key example of this versatile approach we explore information transfer using optical communication. We demonstrate both experimentally, theoretically and numerically that the use of a basis set with fields containing optical vortices does not increase the telecommuni...

A known algorithm for modeling quasi-periodic lattices is used to generate two-dimensional quadratic nonlinear photonic quasi-crystals containing a set of desired discrete spectral components. This allows us to fabricate optical devices in which an arbitrary set of nonlinear optical processes can be efficient. We demonstrate this capability by fabricating two devices: a multidirectional single-...

Nondiffracting vector Bessel beams are of considerable interest due to their nondiffracting nature and unique high-numerical-aperture focusing properties. Here we demonstrate their creation by a simple procedure requiring only a spatial light modulator and an azimuthally varying birefringent plate, known as a q-plate. We extend our control of both the geometric and dynamic phases to perform a p...

This paper will give an overview about the Transportable Optical Ground Station (TOGS) of DLR’s Institute of Communications and Navigation. Furthermore, a short description of its project involvement will be given. OCIS codes: (060.4510) Optical communications; (200.2605) Free-space optical communication