lessons learned from fqpm & aic p. baudoz, a. boccaletti, d. rouan, d. mawet & coronagraphy...
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Lessons Learned from FQPM & AIC
P. Baudoz, A. Boccaletti, D. Rouan, D. Mawet & Coronagraphy team @
Observatoire de Paris-Meudon
Achromatic Interfero Coronagraph
- 1996 : 10 years
OCA-STScI-ONERA 1997OCA-STScI-ONERA 1997
Separation = 1/3 of /D, K = 3.5
D=34r0(vis)
OCA-STScI-ONERA 1997
Gay & Rabbia 1996,CRAS ; Baudoz et al., 2000a, A&A ; Baudoz et al., 2000b, A&A
CIA @ CFHT
Baudoz et al., 2000, CFHT Bulletin
Adapting coronagraph to a existing design
here CFHT telescope: highly not optimized (secondary mirror > 30%)
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
FQPM Visible Lab tests
10-6 @ 3/D
Riaud et al. 2003, PASP
Limited by an ocean of speckle at the 10-6 level
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
FQPM @ VLT
Boccaletti et al. ,2007, in preparation
Information up to 13 AU (instead of 23 AU with Lyot coronagraph)
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
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)
0 200 400 600 800 µm
µm
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nm
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ZnSe deposition15m 4QPM
Diamond RIE 5m 4QPM
1 m
/D = 300m
GE RIE15m 4QPM
Baudoz et al., 2005b, PASP
10-5
FQPM Mid-Infrared Test @ 5m for MIRI/JWST
Precise information on optical materials unknown at very low temperature for these bandwidths
FQPM Achromatization - Halfwave plate
Development in the context of SPHERE (VLT Planet finder)
Mawet et al, 2006
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
• 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