Lichtgedanken 04

S C HW E R P U N K T 24 Staff at an architecture firm are stand- ing together, discussing a project. A three-dimensional illustration of the planned building shines in the centre of them. »Why not move the entrance ten metres to the left and the lift to the east wing—then there would be more space for a larger terrace«, one architect says to another. The person addressed moves his hands through the air like a conductor, causing the virtual walls of the model to move and come together in a different position. Admittedly, this scene has not yet happened. Architects continue toworkwith drawings on large sheets of paper, look at two-dimensional diagrams on a screen or create designs using models that require a lot of time and energy to produce. Yet, what may currently seem like science fiction, may actually be an everyday tool for many occupations in just a few years’ time. At least, if things go as Prof. Dr Stefan Nolte from the Institute of Applied Physics thinks they might. Together Drawing with luminous air Measuring objects in 3D no longer poses any technical problems—but presenting them in three dimensions remains an issue. You generally need to wear special glasses or have to accept viewing a two-dimen­ sional image on a flat surface. Jena physicists have now developed a method to present 3D objects in thin air using laser beams. BY SEBASTIAN HOLLSTEIN with his colleagues Dr Robert Kammel and Dr Roland Ackermann, he is work- ing with the »Ultrafast Optics« working group to develop a new technology to present three-dimensional objects in thin air. This is all part of the project consortium »3Dsensation«. »In this al- liance, we want to work together with partners from various scientific fields to develop technologies, which will im- prove the interaction between humans and machines, and will thus have a posi­ tive effect on people’s lives and work«, says Stefan Nolte, explaining the vision behind »3Dsensation«. One of the basic premises of this is being able to present three-dimensional objects in actual 3D. »There are currently several ways of capturing objects in 3D and generating coordinates for their three-dimensional representation. Medics now utilise the corresponding imaging processes on a daily basis«, explains Robert Kammel. »Yet, until now, it has not been possible to adequately present this information in 3D. Often, we have to make do with a two-dimensional image on a flat screen, or the images have to be generated with the help of displays and can only be viewed using special glasses.« An invisible laser ionizes the air— mirrors move light points quickly As part of the project »DiRLas—Un- tersuchungen zur Visualisierung von 3D-Objekten im freien Raum mittels Laser« (DiRLas—investigations into the visualisation of 3D objects in free space using lasers), Nolte, Kammel and Ack- ermann have now developed a very promising method. It involves the use of a femtosecond laser; in other words, a laser, which emits very short laser pulses. The light emitted is in the in- frared range and is thus invisible to the human eye. The scientists use a lens to focus the laser beam on a specific point