Mathieu beams as versatile light moulds for 3D micro particle assemblies

We present tailoring of three dimensional light fields which act as light moulds for elaborate particle micro structures of variable shapes. Stereo microscopy is used for visualization of the 3D particle assemblies. The powerful method is demonstrated for the class of propagation invariant beams, where we introduce the use of Mathieu beams as light moulds with non-rotationally-symmetric structure. They offer multifarious field distributions and facilitate the creation of versatile particle structures. This general technique may find its application in micro fluidics, chemistry, biology, and medicine, to create highly efficient mixing tools, for hierarchical supramolecular organization or in 3D tissue engineering

Roadmap on structured light

Structured light refers to the generation and application of custom light fields. As the tools and technology to create and detect structured light have evolved, steadily the applications have begun to emerge. This roadmap touches on the key fields within structured light from the perspective of experts in those areas, providing insight into the current state and the challenges their respective fields face. Collectively the roadmap outlines the venerable nature of structured light research and the exciting prospects for the future that are yet to be realized

Holographic optical tweezers induced hierarchical supramolecular organization

Nanocontainers, i.e. particles at the micro and nano scale that can host guest molecules, are of highest interest for various applications especially in nanoscience and biomedicine. Popular examples are the delivery of phar-maceuticals or active agents to specific cell, nerve or tissue domains or the organization of larger scaffolds of artificial matter by arrangements of nancontainers [1]. While in some applications the precise control of the position of individual nanocontainers is negligible, it becomes most important for hierarchical supramolecular organisation. Here, microporous nanocontainers are loaded with guest molecules that are not covalently bound, but occupy cavities of highest geometrical order, and this order is directly transferred to the molecules. The order can be extended from the molecular to the microscopic scale by arranging and organizing the nanocontainers themselves - usually by self-assembly or by chemical means

Dynamic modulation of Poincaré beams

Generation of complex Poincaré beams is enabled by amplitude and phase modulation accompanied by simultaneous spatially polarization structuring. A holographic system to tailor complex light fields and optical angular momentum structures forecasts promising applications in quantum communication and optical trapping. Experimental results are presented together with simulations of complex Poincaré beams embedding different types of polarization singularities. Additionally, parameters of the dynamic polarization modulation system are discussed and analyzed to demonstrate the enormous capability of the method

Conical Refraction Bottle Beams for Entrapment of Absorbing Droplets

Conical refraction (CR) optical bottle beams for photophoretic trapping of airborne absorbing droplets are introduced and experimentally demonstrated. CR describes the circular split-up of unpolarised light propagating along an optical axis in a biaxial crystal. The diverging and converging cones lend themselves to the construction of optical bottle beams with flexible entry points. The interaction of single inkjet droplets with an open or partly open bottle beam is shown implementing high-speed video microscopy in a dual-view configuration. Perpendicular image planes are visualized on a single camera chip to characterize the integral three-dimensional movement dynamics of droplets. We demonstrate how a partly opened optical bottle transversely confines liquid objects. Furthermore we observe and analyse transverse oscillations of absorbing droplets as they hit the inner walls and simultaneously measure both transverse and axial velocity components