Dresden 2020 – scientific programme
The DPG Spring Meeting in Dresden had to be cancelled! Read more ...
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 124: Development of Novel Methods II
O 124.1: Talk
Friday, March 20, 2020, 10:30–10:45, WIL C107
Michelson Interferometry with Spiral Phase Plates — •Michael Reichenspurner1, Nicola Kerschbaumer1, Michael Fedoruk2, Theobald Lohmüller1, and Jochen Feldmann1 — 1Chair for Photonics and Optoelectronics, Nano-Institute Munich and Department of Physics, Ludwig-Maximilians-Universität, Königinstr. 10, 80539 Munich, Germany — 2Vortex Photonics, Lindwurmstr. 115, 80337 Munich, Germany
Interferometry for highly accurate distance or surface profile measurements is widely applied in various fields of research and engineering. The basic principle of most interferometric approaches is that two propagating transverse beams are superimposed to generate a Newton*s rings interference pattern. Here, we demonstrate a different idea, using an optical vortex instead of a transverse beam for distance measurements in a Michelson configuration. By using a spiral phase plate, we generate a donut-shaped laser beam with helical propagation. The interference of two such helical beams, when they have opposite rotations, results in a characteristic flower shaped intensity distribution. Any phase difference introduced between these beams, either by a length difference or a change in refractive index in one of the beam paths, leads to a specific rotation of the flower pattern, which is even observable by the naked eye.