1. Design Team Report: Laser Facility Chris Neyman Jim Bell, Erik Johansson, Jason Chin W. M. Keck Observatory Viswa Velur Caltech Optical Observatories Keck NGAO Team Meeting #12 December 13, 2007 Videoconference

2. 2 Agenda New Lead –Transition from Chin to Neyman Status of WBS elements Plan for finishing

3. 3 WBS 3.3 Laser 3.3.1 Laser Architecture 3.3.2 Laser Enclosure 3.3.3 “Laser” 3.3.4 Laser Launch Facility 3.3.5 Laser safety 3.3.6 Control system (See Non RTC talk this meeting)

4. 4 WBS 3.3.1 Laser Architecture Down selection to a “feasible” design based on our current understanding of available lasers and associated technologies –Not necessary final design or best design –Based on original estimate of LGS return from wavefront error budget –Details on AOSystemDesign TWiki at: http://www.oir.caltech.edu/twiki_oir/pub/Keck/NGAO/AOSystemDesign/NGAO_Preliminary_Conceptual_Laser_Architecture_v1_3.doc http://www.oir.caltech.edu/twiki_oir/pub/Keck/NGAO/AOSystemDesign/NGAO_Preliminary_Conceptual_Laser_Architecture_v1_3.doc –Selected Architecture 2 SOR type CW lasers 75W each –Circular polarization –D2a and D2b pumping Free space optical relay Laser heads mounted on elevation ring Power supplies mounted on Nasmyth platform Launch telescope behind secondary mirror

5. 5 WBS 3.3.2 Laser Enclosure Requirements updated Jim Bell working on enclosure design

6. 6 WBS 3.3.3 the “Laser” Updated laser requirement Draft report on expected laser return by Velur and Dekany should be finalized soon

7. 7 WBS 3.3.4 Laser Launch Free space beam propagation Based on current K1 LGS Design for flexibility in laser power and number LGS See Cartoon next page Concept needs to be verified and specifications documented

8. 8 Add cartoon of beam transport system

9. 9 WBS 3.3.5 Laser safety Based on current procedure and practices at Keck See related linked documents at: http:// www.oir.caltech.edu/twiki_oir/bin/view.cgi/Keck/NGAO/AOSystemDesign http:// www.oir.caltech.edu/twiki_oir/bin/view.cgi/Keck/NGAO/AOSystemDesign Sufficient to show “feasibility” for system design

10. 10 Completion of WBS 3.3.Laser To do: –Finalize baseline power and operating margin (VV, RD, etc.) –Complete beam transport design (CN, JB) –Complete enclosure design (JB) –Close out design in early 08