Philipp Hottinger (Germany)
phottinger @ lsw.uni-heidelberg.de
Development of photonic reformattors for astronomy
Astrophotonics is an emerging field of astronomical instrumentation. The goal is to design, manufacture and test integrated optics that will replace parts of conventional bulk optics at telescopes. My research focusses on photonic components for spectrographs. As future spectrographs will not only be required to process light from 40m telescopes, but also to reach radial velocity precisions of cm/s. Yet, due to the seeing in the atmosphere, light that is captured by the telescope is not diffraction limited but seeing limited. The Point-Spread-Function (PSF) of a light source is then spread out rather than being an Airy disk. Adaptic optics has been able to reduce this impact but it is not yet possible to feed this light into a single-mode fiber without substantial loss of throughput. Instead light is coupled into multi-mode fibers which puts additional restraints on the subsequent instruments such as spectrographs. Photonic devices such as reformatters can be used transform light signals from one multi-mode fiber to several single-mode fibers. These signals can then be fed into spectraphs reducing the requirements to processing single mode signals. I work on developing and testing and manufacting such devices for future use at ground based telescopes.
Supervisor: Andreas Quirrenbach (LSW)