Siddharth Ramachandran DTU-Fotonik; Danish Technical University Non-Zero-Order Light: Beams that can do what a Gaussian cannot Time: May 28, 15.15 to 16.00 Place: Fys. Aud. When we think of laser light, we think of a beam that looks like a spot, or more precisely, like a Gaussian. This ground state solution, in free space, resonators, waveguides, etc., has several well-known properties ? for instance they diffract, carry energy (or momentum) in the direction of the beam, are blocked by opaque obstructions, etc. However, many of these properties are dramatically altered if one were able to generate and stably propagate beams that are higher-order, spatially variant solutions of an optical system. For instance, certain non-uniform polarisation distributions of light, when focussed, result in beams that carry no energy along the optic axis. Alternatively, beams with special Bessel-functional profiles can be shown to be strictly diffraction-free, and can even navigate around dark objects. This talk will introduce the physics of such interesting beam shapes. In particular, we will describe how an optical fiber is an attractive, and perhaps in many cases the only, means to realise these solutions. We will discuss the utility of such fiber devices, both from the standpoint of studying fundamental physical phenomena and quantum systems, and from the standpoint of realising novel devices with applications in emerging areas such as sensing, high-power lasers and biology. Peter Staanum and Nicolai Nygaard Coffee, tea and cake will be served at 15.05 ---------------------------------- Peter Frøhlich Staanum Department of Physics and Astronomy University of Aarhus Ny Munkegade 120 8000 Aarhus C Denmark Phone: (+45) 8942 3602 Fax: (+45) 8612 0740 VAT Nr.: DK16562777 EAN Nr.: 5798000419872 ----------------------------------