HOME

Molar Root Canal Measuring
The root canal of a patient's molar is measured using VR techniques.

Molecular dynamics
Coupling and steering a molecular dynamics simulation to a virtual reality system.

Electrical Potential
Interactively showing the local electric field surface within a molecule

The Sisyphus Attractor
The multidimensional parameter space of a diode laser feedback system is analyzed extensively in VR.

Robot Soccer
Interaction and long-distance collaboration made possible with visualized autonomous agents using VR.

Measuring Robots
Mobile autonomous robots in a hostile environment are analyzed and controlled in virtual reality.

Visible Human
3D reconstruction of a large dataset using a "Marching Cubes" technique.

Laser Diode Simulation

Another application we implemented is the visualization of a diode laser behavior, referred to as the Sisyphus Attractor. Numerical simulations are performed for a semiconductor diode laser, subject to optical feedback. Due to the feedback, the resulting dynamical system has infinite degrees of freedom. The exploration and investigation of such a large data set calls for the immersion of the user into a representation of the parameter space. A simulation run generates a trajectory in such a space. In the 3D space provided by CAVEStudy, we decided to focus on the most natural phase space from the physical point of view (the output power, the inversion, and the phase difference).

A previous study on the visualization of this simulation already gave a better insight into the dynamical behavior of the laser, but suffered severely from lack of interaction. With CAVEStudy, we linked the simulation running on an IBM SP2 to our CAVE. In a first step, the simulation computes some fixed points in the phase space for a given set of parameters. The user can interactively set the values of selected parameters using sliders. The fixed points serve as starting point of the simulation. These points are visualized, and the scientist can directly select one of these points to start the simulation. The computed trajectory is sent incrementally to the CAVE. The trajectory is visualized and can be manipulated by the scientist. The simulation can be stopped and re-started using a new starting fixed-point or different parameter values.

CAVEStudy's benefits are many-fold in this case; it is easier to use than a previous approach (batch-processing and offline visualization); the study of the initial-condition sensitivity of the laser is enhanced by the ability to modify the parameters of the simulation interactively; since our system does not require modifications of simulation code, we can deal very easy with the changes of a code still revised frequently; the interactive way in which physicists could test hypotheses and investigate the behavior of the diode laser helped them to gain a better insight in this complex system.