A Short Presentation of Ongoing AO Work at Lund Observatory Mette Owner-Petersen Lund Observatory Workshop for “Forskarskolen i Rymdteknik” Gothenburg 12/9 – 13/9 Gothenburg Adaptive Optics

What is Adaptive Optics? Answer: Real-time Improvement of the Quality of Images which are degraded due to dynamical perturbations of the imaging system

 Peak Intensity (Strehl Ratio)  Resolution (FWHM)  Contrast (Background Level) Strehl Ratio: Detection of faint objects FWHM:Resolving bright objects in crowded fields Contrast:Direct Exo-Planet observation What is Meant by Image Quality? Point Image (PSF)

A Generic Example of Adaptive Optics

The Shack-Hartmann Wavefront Sensor Other design principles are possible

How it looks in Reality From the William Herschel telescope on La Palma

With and Without Adaptive Optics

Different AO Modes  Single Conjugate Adaptive Optics (SCAO). One DM and one guide star -> High Strehl but small corrected field.  Ground Layer Adaptive Optics (GLAO). The easy game. One DM and several guide stars -> Low Strehl but narrow FWHM over large field.  Multi Conjugate Adaptive Optics (MCAO). Several DMs and several guide stars -> High Strehl and large corrected field.  Extreme Adaptive Optics (ExAO). The hard bargain One DM and one Guide Star. Complicated filtering in both image and pupil plane -> Extremely high contrast.

SCAO versus MCAO Uncorrected SCAO MCAO

How to Make it Work  Analytical performance evaluation  Confirmation by simulations  Lab verifications if needed  Optical modeling  “The real thing”

 Simulations of AO perfomance for the Euro50. Integrated modeling PhD project for Anita Enmark  DCAO on the Lunda – Moon and for terrestrial applications Collaboration with Dept. of Applied Optics in Galway and FOI Sweden PhD project for Per Knutsson  DCAO for wide - field retinal imaging Collaboration with Dept. of Ophthalmology in Gothenburg  Previous: Analytical performance evaluations Experimental verification of expected DCAO performance Ongoing AO Work

Correction for Atmosphere La Palma 7-Layer Model 0 s < t < 0.1 sNo AO correction 0.1 s < t < 0.6 sSlow correction for Focus & Tip/tilt 0.6 s < t < 1.1 sAO ON Specification for AO: Strehl > 0.58 Euro50 λ=2.2 μm Scale 0  0.3

The Moon DCAO Experiment Zemax Model Celestron DM1 0 km DM2 10 km Sci. Cam. Tip /Tilt WFS

Wide Field Retinal Imaging First light very soon!

Goal of the experiment: Emulation of K – band performance of SCAO, GLAO and DCAO on a 7.5 m telescope 5 guide stars in a cross Specific Address: Field gain going from SCAO to DCAO The Lund DCAO Demonstrator