| 31 | 31 | || 10.10.2014 || '''Casey Deen''' || '''Alignment challenges and strategies for the GRAVITY wavefront sensor cryostat and tower[[BR]]'''[[BR]]Aligning a handful of small mirrors,filters, and lenses with a laser shouldn't be so difficult, right? Surely no more than an afternoon! But after another week spent huddled in a dark laboratory, the light still does not end up in the correct position on the detector! In order to avoid this frustrating situation, an alignment strategy is an important part of building any instrument. Casey Deen presents the alignment concept for the GRAVITY wavefront sensor. This near-infrared sensor works on the Shack-Hartman Principle. Due to their wavelength range, near-infrared sensors have a larger selection of bright guide stars than do optical sensors, as most stars are brightest in the infrared. Optical light is also attenuated more by interstellar dust, making optical sensors impractical in dusty regions like the Galactic Center. The wavefront sensors are located in the Coude rooms of the Unit Telescopes of the Very Large Telescope (VLT). The location and the optical design of the wavefront sensors present severalchallenges for alignment. Casey and his colleagues present their strategy for alignment of the optics, and are looking forward to hearing opinions, advice and concerns from the assembled experts at MPIA. Expect a lively discussion and insight on what is laboratory work about! [[BR]][[BR]]Talk: Englisch [[BR]]Slides: German[[BR]]Questions: German, Englisch || |
