ztfc 12-segment field flattener (and related) options
DESCRIPTION
ZTFC 12-segment field flattener (and related) options. R. Dekany 07 Aug 2012. ZTF Camera. Goal from last discussion was a practical design that covers 12 wafer-scale CCD’s with FWHM ≤ 1.1 arcsec for each band Avenues identified as promising Chorded CCD positioning (along best-fit sphere) - PowerPoint PPT PresentationTRANSCRIPT
ZTFC 12-segment field flattener (and related) options
R. Dekany07 Aug 2012
ZTF Camera
• Goal from last discussion was a practical design that covers 12 wafer-scale CCD’s with FWHM ≤ 1.1 arcsec for each band
• Avenues identified as promising– Chorded CCD positioning (along best-fit sphere)
• To mitigate field curvature driving down flattener thickness– Segmented field flattener / segmented dewar window– 32 4K’s vs. 12 10K’s for the options above– Wide-field corrector options
C a l t e c h O p t i c a l O b s e r v a t o r i e sR i c h a r d D e k a n y
v 3 _ z t f c _ 1 2 s e g m e n t e d _ f l a t t e n e r _ m e n i s c u s M o n o A s p h e r e W i n d o w _ m e n i s c u s F i l t e r _ S S K N 5 _ 6 m i c r o n _ 2 0 0 m m . Z M X
3 D L a y o u tZ T F C8 / 6 / 2 0 1 2
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Consider the class of solutions:12 chorded CCDs, each with its own thin field flattenerGlobal meniscus dewar window w/ 1 aspheric surfaceMeniscus filter (exchangeable)
Image quality improves as window & filterare allowed to move away from prime focus
Question: What does this solution space look like?
Telescope clamshell shutter option (not necessary, but available if it eases prime congestion)
C a l t e c h O p t i c a l O b s e r v a t o r i e sR i c h a r d D e k a n y
v 3 _ z t f c _ 1 2 s e g m e n t e d _ f l a t t e n e r _ m e n i s c u s M o n o A s p h e r e W i n d o w _ m e n i s c u s F i l t e r _ S S K N 5 _ 6 m i c r o n _ 2 0 0 m m . Z M X
3 D L a y o u tZ T F C8 / 6 / 2 0 1 2
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12 CCDs on chorded mount
1 field flattenerper CCD
Aspheric dewarwindow
(design also allows for segmented dewar
window strategies) Meniscus filter (exchangeable)
Prime focusobscuration
Quincunx field ptsfor each CCD
Max Distance Constraint
C a l t e c h O p t i c a l O b s e r v a t o r i e sR i c h a r d D e k a n y
v 3 _ z t f c _ 1 2 s e g m e n t e d _ f l a t t e n e r _ m e n i s c u s M o n o A s p h e r e W i n d o w _ m e n i s c u s F i l t e r _ S S K N 5 _ 6 m i c r o n _ 2 0 0 m m . Z M X
3 D L a y o u tZ T F C8 / 6 / 2 0 1 2
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Equal areal weight optimization(Outer CCD weight = 2x Inner)
C a l t e c h O p t i c a l O b s e r v a t o r i e sR i c h a r d D e k a n y
v 3 _ z t f c _ 1 2 s e g m e n t e d _ f l a t t e n e r _ m e n i s c u s M o n o A s p h e r e W i n d o w _ m e n i s c u s F i l t e r _ S S K N 5 _ 6 m i c r o n _ 1 5 5 m m . Z M X
3 D L a y o u tZ T F C8 / 6 / 2 0 1 2
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C a l t e c h O p t i c a l O b s e r v a t o r i e sR i c h a r d D e k a n y
v 3 _ z t f c _ 1 2 s e g m e n t e d _ f l a t t e n e r _ m e n i s c u s M o n o A s p h e r e W i n d o w _ m e n i s c u s F i l t e r _ S S K N 5 _ 6 m i c r o n _ 2 4 5 m m . Z M X
3 D L a y o u tZ T F C8 / 6 / 2 0 1 2
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“
Conclusions for this class of solution…
• Depending on remainder of error budget, allocation of 1.1 arcsec to design FWHM seems about right
• To exploit good seeing, allow filter vertex to center of FPA distance of ~ 210mm– Implies meniscus filter diameter ~ 520 mm (20.5 inch)
• Near-term to do:– Optimize filter glass choice for g’ and R spectral bands– Worry about coating the meniscus filters for uniform
bandwidth and transmission– Worry about handling / exchanger
Flat CCD, thick dewar window, flat filter, plus corrector
(A more classical option…)
C a l t e c h O p t i c a l O b s e r v a t o r i e sR i c h a r d D e k a n y
v 3 _ z t f c _ f l a t C C D _ b i C o n v e x W i n d o w _ 2 0 F i l t e r _ a s p h e r i c M e n i s c u s _ M e n i s c u s _ i n t e r e s t i n g . Z M X
3 D L a y o u tZ T F C8 / 7 / 2 0 1 2
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Flat CCDfocal plane
Biconvexdewarwindow
Flat filter(exchangeable)
Meniscuscorrector(640mm diam.)
Prime focusobscuration
4 deg maxfield angle
Asphericcorrector
Thick window, flat filter option• Surprisingly good
image quality• FHWM ~ 1.0”• Lots of glass
– Low transmission– Ghosting?– Not verified for R’
(though probably ok)
• Large element– Probably can’t reduce it
much before harming DIQ
S u r f a c e I M A : C C D M o s a i c
60.00
O B J : 0 . 0 0 0 0 , 0 . 0 0 0 0 ( d e g )
I M A : 0 . 0 0 0 , - 0 . 0 0 0 m m
O B J : 0 . 0 0 0 0 , 4 . 0 0 0 0 ( d e g )
I M A : - 0 . 0 0 0 , 2 0 9 . 9 8 5 m m
O B J : 0 . 0 0 0 0 , 3 . 0 0 0 0 ( d e g )
I M A : 0 . 0 0 0 , 1 5 7 . 4 5 4 m m
O B J : 0 . 0 0 0 0 , 2 . 0 0 0 0 ( d e g )
I M A : 0 . 0 0 0 , 1 0 4 . 9 7 9 m m
O B J : 0 . 0 0 0 0 , 1 . 0 0 0 0 ( d e g )
I M A : 0 . 0 0 0 , 5 2 . 4 9 7 m m
0 . 5 3 6 0 0 . 4 6 7 0 0 . 6 1 6 0
C a l t e c h O p t i c a l O b s e r v a t o r i e sR i c h a r d D e k a n y
v 3 _ z t f c _ f l a t C C D _ b i C o n v e x W i n d o w _ 2 0 F i l t e r _ a s p h e r i c M e n i s c u s _ M e n i s c u s _ i n t e r e s t i n g . Z M X
S p o t D i a g r a mZ T F C8 / 7 / 2 0 1 2 U n i t s a r e µ m . A i r y R a d i u s : 1 . 5 8 µ mF i e l d : 1 2 3 4 5R M S r a d i u s : 5 . 2 9 1 1 0 . 6 4 2 6 . 9 2 1 5 . 5 3 8 5 . 3 2 2G E O r a d i u s : 1 2 . 5 9 0 3 3 . 3 1 1 1 9 . 7 6 0 1 7 . 2 8 4 1 4 . 8 1 1S c a l e b a r : 6 0 R e f e r e n c e : C e n t r o i d
Equiconcave aspheric window + Plano-convex filter
(A minimal optics solution…?)
C a l t e c h O p t i c a l O b s e r v a t o r i e sR i c h a r d D e k a n y
v 3 _ z t f c _ 1 2 s e g m e n t e d _ f l a t t e n e r _ b i C o n c a v e M o n o A s p h e r e W i n d o w _ p l a n o C o n v e x F i l t e r _ 2 1 5 m m _ n i c e _ c o m p r o m i s e . Z M X
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12 CCDs on chorded mount
1 field flattenerper CCD
Fused silicaaspheric dewarwindow(equiconcave)
Plano-convex filter (exchangeable)
Prime focusobscuration
Quincunx field ptsfor each CCD
Equiconcave aspheric window + Plano-convex filter
• Field-averagedFWHM = 1.12”
• Comfortable cryostat window
• All fused silica• One plano filter
surface– Easier coating?– 542 mm diam.
• Other concerns– ‘Contact lens’ ghosts…
S u r f a c e I M A : C C D M o s a i c60.00
O B J : 0 . 0 0 0 0 , 3 . 5 7 8 0 ( d e g )
I M A : - 4 7 . 9 6 6 , 4 7 . 2 5 9 m m
O B J : 0 . 0 0 0 0 , 1 . 7 8 9 0 ( d e g )
I M A : - 4 7 . 9 6 5 , - 4 8 . 5 3 8 m m
O B J : 1 . 7 8 9 0 , 1 . 7 8 9 0 ( d e g )
I M A : 4 7 . 5 5 4 , - 4 8 . 4 0 4 m m
O B J : 0 . 8 9 4 5 , 2 . 6 8 3 5 ( d e g )
I M A : - 0 . 2 4 9 , - 0 . 6 5 4 m m
O B J : 1 . 7 8 9 0 , 3 . 5 7 8 0 ( d e g )
I M A : 4 7 . 4 7 8 , 4 7 . 3 5 6 m m
0 . 5 3 6 0 0 . 4 6 7 0 0 . 6 1 6 0
C a l t e c h O p t i c a l O b s e r v a t o r i e sR i c h a r d D e k a n y
v 3 _ z t f c _ 1 2 s e g m e n t e d _ f l a t t e n e r _ b i C o n c a v e M o n o A s p h e r e W i n d o w _ p l a n o C o n v e x F i l t e r _ 2 1 5 m m _ n i c e _ c o m p r o m i s e . Z M X
S p o t D i a g r a mZ T F C8 / 6 / 2 0 1 2 U n i t s a r e µ m . A i r y R a d i u s : 1 . 5 9 7 µ mF i e l d : 1 2 3 4 5R M S r a d i u s : 9 . 8 0 9 7 . 0 1 3 7 . 7 8 2 7 . 2 2 6 1 0 . 4 8 5G E O r a d i u s : 3 0 . 5 9 0 2 0 . 5 5 2 2 2 . 3 9 0 2 0 . 7 3 4 3 5 . 2 2 2S c a l e b a r : 6 0 R e f e r e n c e : C e n t r o i d
System/Prescription Data
File : C:\Users\Richard Dekany\Documents\COO\Projects\PTF2\Optical Design\v3_ztfc_12segmented_flattener_equiConcaveMonoAsphereWindow_planoConvexFilter_215mm_nice_compromise.ZMXTitle: ZTFCDate : 8/7/2012Configuration 1 of 2
GENERAL LENS DATA:
Surfaces : 14Stop : 1System Aperture : Entrance Pupil Diameter = 1244.6Glass Catalogs : SCHOTT MISCRay Aiming : OffApodization : Uniform, factor = 0.00000E+000Temperature (C) : 2.00000E+001Pressure (ATM) : 1.00000E+000Adjust Index Data To Environment : OffEffective Focal Length : 3060.123 (in air at system temperature and pressure)Effective Focal Length : 3060.123 (in image space)Back Focal Length : 2.810671Total Track : 6131.702Image Space F/# : 2.45872Paraxial Working F/# : 2.45872Working F/# : 2.453778Image Space NA : 0.1992791Object Space NA : 6.223e-008Stop Radius : 622.3Paraxial Image Height : 135.2147Paraxial Magnification : 0Entrance Pupil Diameter : 1244.6Entrance Pupil Position : 0Exit Pupil Diameter : 516.0726Exit Pupil Position : -1260.556Field Type : Angle in degreesMaximum Radial Field : 2.530028Primary Wavelength : 0.536 µmLens Units : MillimetersAngular Magnification : 2.404811
Fields : 5Field Type : Angle in degrees # X-Value Y-Value Weight 1 0.000000 0.000000 1.000000 2 0.000000 1.789000 1.000000 3 1.789000 1.789000 1.000000 4 0.894500 0.894500 2.000000 5 1.789000 0.000000 1.000000
Wavelengths : 3Units: µm # Value Weight 1 0.536000 0.850000 2 0.467000 0.900000 3 0.616000 0.850000
SURFACE DATA SUMMARY:
Surf Type Radius Thickness Glass Diameter Conic Comment OBJ STANDARD Infinity Infinity STO STANDARD 117054.9 11.481 LLF6 1244.6 0 CORRECTOR 2 EVENASPH 64570.28 17.2206 BK7 1260 0 CORRECTOR 3 EVENASPH 173900.9 2751.5 1260 0 CORRECTOR 4 STANDARD Infinity 3351.5 1260 0 5 STANDARD -6123.94 -2700 MIRROR 1782.416 0 M1 6 STANDARD Infinity -140.5651 449.6796 0 7 STANDARD -2985.008 -18.06109 F_SILICA 375.5883 0 8 STANDARD Infinity -109.3336 370.9474 0 9 EVENASPH 2168.138 -15.84882 F_SILICA 311.0921 0 10 STANDARD -2168.138 -67.32618 302.268 0 11 COORDBRK - 0 - - Marginal Focus 12 STANDARD -963.5794 -6.01121 F_SILICA 137.6897 0 13 STANDARD 2251.796 -1.649183 137.6897 0 IMA STANDARD Infinity 135.7214 0 CCD Mosaic
Surface 9 EVENASPH Coeff on r 2 : -4.2364504e-005Coeff on r 4 : -1.9236429e-010Coeff on r 6 : -6.9743573e-017
Similar 4-segment solution?
C a l t e c h O p t i c a l O b s e r v a t o r i e sR i c h a r d D e k a n y
v 3 _ z t f c _ 4 s e g m e n t e d _ f l a t t e n e r _ e q u i C o n c a v e M o n o A s p h e r e W i n d o w _ p l a n o C o n v e x F i l t e r _ 2 7 0 m m _ n o t _ a s _ n i c e _ c o m p r o m i s e . Z M X
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• Solution doesn’t work as well for 4-segment flattener
• Design FWHM ~ 2.0”
S u r f a c e I M A : C C D M o s a i c60.00
O B J : 0 . 0 0 0 0 , 0 . 0 0 0 0 ( d e g )
I M A : - 9 5 . 6 5 9 , - 9 5 . 8 0 3 m m
O B J : 0 . 0 0 0 0 , 3 . 5 7 8 0 ( d e g )
I M A : - 9 5 . 6 5 8 , 9 5 . 3 7 3 m m
O B J : 3 . 5 7 8 0 , 3 . 5 7 8 0 ( d e g )
I M A : 9 5 . 2 3 5 , 9 5 . 3 7 9 m m
O B J : 1 . 7 8 9 0 , 1 . 7 8 9 0 ( d e g )
I M A : - 0 . 2 4 4 , - 0 . 2 4 4 m m
O B J : 3 . 5 7 8 0 , 0 . 0 0 0 0 ( d e g )
I M A : 9 5 . 5 1 7 , - 9 5 . 5 1 4 m m
0 . 5 3 6 0 0 . 4 6 7 0 0 . 6 1 6 0
C a l t e c h O p t i c a l O b s e r v a t o r i e sR i c h a r d D e k a n y
v 3 _ z t f c _ 4 s e g m e n t e d _ f l a t t e n e r _ e q u i C o n c a v e M o n o A s p h e r e W i n d o w _ p l a n o C o n v e x F i l t e r _ 2 7 0 m m _ n o t _ a s _ n i c e _ c o m p r o m i s e . Z M X
S p o t D i a g r a mZ T F C8 / 6 / 2 0 1 2 U n i t s a r e µ m . A i r y R a d i u s : 1 . 6 0 6 µ mF i e l d : 1 2 3 4 5R M S r a d i u s : 1 1 . 4 4 0 1 3 . 4 4 5 1 2 . 4 3 4 1 2 . 6 6 4 1 3 . 4 3 6G E O r a d i u s : 3 3 . 8 6 8 4 5 . 2 9 0 4 0 . 5 5 1 3 3 . 3 9 1 4 5 . 2 3 1S c a l e b a r : 6 0 R e f e r e n c e : C e n t r o i d
Side note: 4Ks vs. 10Ks…
C a l t e c h O p t i c a l O b s e r v a t o r i e sR i c h a r d D e k a n y
v 3 _ z t f c _ 3 2 s e g m e n t e d _ f l a t t e n e r _ p l a n o C o n c a v e M o n o A s p h e r e F i l t e r _ 1 l e n s C o r r e c t o r _ 5 m i c r o n _ e x c e l l e n t _ c o m p r o m i s e . Z M X
3 D L a y o u tZ T F C8 / 6 / 2 0 1 2
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32 CCDs on chorded mount
1 field flattenerper CCD
Fused silicaaspheric (plano)dewar window
Plano-convex filter (exchangeable)
Prime focusobscuration
Quincunx field ptsfor each CCD
Interesting compromise
• Field-averagedFWHM = 1.07”
• Two ‘Naturally’ plano surfaces
• But…– 4K ROM’s coming in
higher than 10K’s so CCD cost rules out this option
S u r f a c e I M A : C C D M o s a i c60.00
O B J : 0 . 0 0 0 0 , 2 . 1 9 8 0 ( d e g )
I M A : - 3 0 . 5 0 5 , 2 6 . 0 9 5 m m
O B J : 0 . 0 0 0 0 , 1 . 0 9 9 0 ( d e g )
I M A : - 3 0 . 5 0 4 , - 3 2 . 7 7 6 m m
O B J : 1 . 0 9 9 0 , 1 . 0 9 9 0 ( d e g )
I M A : 2 8 . 2 7 9 , - 3 2 . 7 3 9 m m
O B J : 0 . 5 5 0 0 , 1 . 6 4 9 0 ( d e g )
I M A : - 1 . 0 9 5 , - 3 . 3 1 9 m m
O B J : 1 . 0 9 9 0 , 2 . 1 9 8 0 ( d e g )
I M A : 2 8 . 2 7 5 , 2 6 . 1 2 6 m m
0 . 5 3 6 0 0 . 4 6 7 0 0 . 6 1 6 0
C a l t e c h O p t i c a l O b s e r v a t o r i e sR i c h a r d D e k a n y
v 3 _ z t f c _ 3 2 s e g m e n t e d _ f l a t t e n e r _ p l a n o C o n c a v e M o n o A s p h e r e F i l t e r _ 1 l e n s C o r r e c t o r _ 5 m i c r o n _ e x c e l l e n t _ c o m p r o m i s e . Z M X
S p o t D i a g r a mZ T F C8 / 6 / 2 0 1 2 U n i t s a r e µ m . A i r y R a d i u s : 1 . 6 0 6 µ mF i e l d : 1 2 3 4 5R M S r a d i u s : 7 . 6 7 7 5 . 8 2 7 6 . 5 6 1 5 . 8 4 3 7 . 7 6 6G E O r a d i u s : 2 4 . 2 0 0 1 7 . 8 8 2 1 8 . 1 0 3 1 4 . 0 5 0 2 4 . 6 7 4S c a l e b a r : 6 0 R e f e r e n c e : C e n t r o i d