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Published byApril Hodge Modified over 9 years ago
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Lessons Learned from FQPM & AIC P. Baudoz, A. Boccaletti, D. Rouan, D. Mawet & Coronagraphy team @ Observatoire de Paris-Meudon
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Achromatic Interfero Coronagraph - 1996 : 10 years OCA-STScI-ONERA 1997 Separation = 1/3 of /D, K = 3.5 D =34 r 0 (vis) OCA-STScI-ONERA 1997 Gay & Rabbia 1996,CRAS ; Baudoz et al., 2000a, A&A ; Baudoz et al., 2000b, A&A
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CIA @ CFHT Baudoz et al., 2000, CFHT Bulletin Adapting coronagraph to a existing design here CFHT telescope: highly not optimized (secondary mirror > 30%)
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Four Quadrant Phase Mask manufactured and characterized for : -Visible (laboratory R&D) -Near IR (implemented on NACO/VLT) -For mid IR (JWST/MIRI project) -Near IR achromatic version (VLT/SPHERE project) + pupil Rouan et al., 2000, PASP ; Riaud et al., 2001, PASP ; Riaud et al. 2003, PASP
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FQPM Visible Lab tests 10 -6 @ 3 /D Riaud et al. 2003, PASP Limited by an ocean of speckle at the 10 -6 level
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FQPM @ VLT Boccaletti et al.,2004, PASP ; Boccaletti et al.,2007, in preparation HIP 1306 = 0.128’’ – 1.075’’ m = 1.6 – 3.5mag seeing = 0.9’’ raw image centrosymmetrical subtraction Contrast of 10 -4 @ 0.5 ’’ A new device coupled with differential imaging will be implemented
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FQPM @ VLT Boccaletti et al.,2007, in preparation Information up to 13 AU (instead of 23 AU with Lyot coronagraph)
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Active Galactic Nuclei : NGC1068 (Gratadour et al. 2003) New structures revealed at both large and close separations (contrast of known strcutures is improved with respect to previous non-coronagraphic observations) M fov=3.5‘’ Ks+4QPM, fov= 11.7‘’Ks+4QPM, fov=3.5‘’ Large scale arclects structures (d=160pc) micro spieal arms (d=15pc) south tail aligned knots NACO + 4QPM in Ks
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Phase mask manufacturing (JWST-MIRI) possible manufacturing process : ZnSe deposition (lift off) Ge attack (reactive ion etching) ZnSe attack (reactive ion etching) Diamond attack (reactive ion etching) ZnSe deposition 15 m 4QPM Diamond RIE 5 m 4QPM 1 m /D = 300 m GE RIE 15 m 4QPM
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Baudoz et al., 2005b, PASP 10 -5 FQPM Mid-Infrared Test @ 5 m for MIRI/JWST Precise information on optical materials unknown at very low temperature for these bandwidths
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FQPM Achromatization - Halfwave plate Development in the context of SPHERE (VLT Planet finder) Mawet et al, 2006
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FQPM - Visible Halfwave plate lab tests Contrast 10 -5 @ 4 /D for large bandwidth Expected contrast 10 to 100 times better with optimized half wave plate and R=5 to 20 MgF2 50 µm Prototypte IR Halfwave FQPM for SPHERE/VLT Technique limited to 10 -6 to 10 -7 for large bandwidth Mawet et al, 2006
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AR Coatings image ghosts pupil ghosts Optical quality of substrate Fabrication specs transition thickness of quadrant (chromaticity) reproductibility of the specs Low temperature behaviour (optical index) Telescope Specs (JWST, ground, etc…) Moving specs (not in the right direction in general…) Up to now : Adapt coronagraph to telescope TPF-C : MUST NOT DO the opposite but Design telescope and coronagraph together Lessons Learned with AIC & FQPM Development
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