Abstract

Full aperture testing of large cryogenic optical systems has been impractical due to the difficulty of operating a large collimator at cryogenic temperatures. The Thermal Sieve solves this problem by acting as a thermal barrier between an ambient temperature collimator and the cryogenic system under test. The Thermal Sieve uses a set of thermally controlled baffles with array of holes that are lined up to pass the light from the collimator without degrading the wavefront, while attenuating the thermal background by nearly 4 orders of magnitude. This paper provides the theory behind the Thermal Sieve system, evaluates the optimization for its optical and thermal performance, and presents the design and analysis for a specific system.

© 2012 OSA

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. M. Clampin, “Status of the James Webb Space Telescope (JWST),” Proc. SPIE 7010, 70100L, 70100L-7 (2008).
    [CrossRef]
  2. D. M. Chaney, J. B. Hadaway, J. Lewis, B. Gallagher, and B. Brown, “Cryogenic performance of the JWST primary mirror segment engineering development unit,” Proc. SPIE 8150, 815008, 815008-12 (2011).
    [CrossRef]
  3. S. C. West, S. H. Bailey, J. H. Burge, B. Cuerden, J. Hagen, H. M. Martin, and M. T. Tuell, “Wavefront control of the Large Optics Test and Integration Site (LOTIS) 6.5m collimator,” Appl. Opt. 49(18), 3522–3537 (2010).
    [CrossRef] [PubMed]
  4. D. W. Kim and J. H. Burge, “cryogenic thermal mask for space-cold optical testing for space optical systems,” in OF&T, OSA Technical Digest Series (Optical Society of America), FTuS2 (2010).
  5. S. B. Hutchison, A. Cochrane, S. McCord, and R. Bell, “Update status and capabilities for the LOTIS 6.5 meter collimator,” Proc. SPIE 7106, 710618, 710618-12 (2008).
    [CrossRef]
  6. E. Hecht, Optics, 4th ed. (Pearson Education, 2002), Chap. 10.
  7. J. Goodman, Introduction to Fourier Optics, 3rd ed. (Roberts & Company Publishers, 2005), Chap. 4.

2011 (1)

D. M. Chaney, J. B. Hadaway, J. Lewis, B. Gallagher, and B. Brown, “Cryogenic performance of the JWST primary mirror segment engineering development unit,” Proc. SPIE 8150, 815008, 815008-12 (2011).
[CrossRef]

2010 (1)

2008 (2)

M. Clampin, “Status of the James Webb Space Telescope (JWST),” Proc. SPIE 7010, 70100L, 70100L-7 (2008).
[CrossRef]

S. B. Hutchison, A. Cochrane, S. McCord, and R. Bell, “Update status and capabilities for the LOTIS 6.5 meter collimator,” Proc. SPIE 7106, 710618, 710618-12 (2008).
[CrossRef]

Bailey, S. H.

Bell, R.

S. B. Hutchison, A. Cochrane, S. McCord, and R. Bell, “Update status and capabilities for the LOTIS 6.5 meter collimator,” Proc. SPIE 7106, 710618, 710618-12 (2008).
[CrossRef]

Brown, B.

D. M. Chaney, J. B. Hadaway, J. Lewis, B. Gallagher, and B. Brown, “Cryogenic performance of the JWST primary mirror segment engineering development unit,” Proc. SPIE 8150, 815008, 815008-12 (2011).
[CrossRef]

Burge, J. H.

Chaney, D. M.

D. M. Chaney, J. B. Hadaway, J. Lewis, B. Gallagher, and B. Brown, “Cryogenic performance of the JWST primary mirror segment engineering development unit,” Proc. SPIE 8150, 815008, 815008-12 (2011).
[CrossRef]

Clampin, M.

M. Clampin, “Status of the James Webb Space Telescope (JWST),” Proc. SPIE 7010, 70100L, 70100L-7 (2008).
[CrossRef]

Cochrane, A.

S. B. Hutchison, A. Cochrane, S. McCord, and R. Bell, “Update status and capabilities for the LOTIS 6.5 meter collimator,” Proc. SPIE 7106, 710618, 710618-12 (2008).
[CrossRef]

Cuerden, B.

Gallagher, B.

D. M. Chaney, J. B. Hadaway, J. Lewis, B. Gallagher, and B. Brown, “Cryogenic performance of the JWST primary mirror segment engineering development unit,” Proc. SPIE 8150, 815008, 815008-12 (2011).
[CrossRef]

Hadaway, J. B.

D. M. Chaney, J. B. Hadaway, J. Lewis, B. Gallagher, and B. Brown, “Cryogenic performance of the JWST primary mirror segment engineering development unit,” Proc. SPIE 8150, 815008, 815008-12 (2011).
[CrossRef]

Hagen, J.

Hutchison, S. B.

S. B. Hutchison, A. Cochrane, S. McCord, and R. Bell, “Update status and capabilities for the LOTIS 6.5 meter collimator,” Proc. SPIE 7106, 710618, 710618-12 (2008).
[CrossRef]

Lewis, J.

D. M. Chaney, J. B. Hadaway, J. Lewis, B. Gallagher, and B. Brown, “Cryogenic performance of the JWST primary mirror segment engineering development unit,” Proc. SPIE 8150, 815008, 815008-12 (2011).
[CrossRef]

Martin, H. M.

McCord, S.

S. B. Hutchison, A. Cochrane, S. McCord, and R. Bell, “Update status and capabilities for the LOTIS 6.5 meter collimator,” Proc. SPIE 7106, 710618, 710618-12 (2008).
[CrossRef]

Tuell, M. T.

West, S. C.

Appl. Opt. (1)

Proc. SPIE (3)

M. Clampin, “Status of the James Webb Space Telescope (JWST),” Proc. SPIE 7010, 70100L, 70100L-7 (2008).
[CrossRef]

D. M. Chaney, J. B. Hadaway, J. Lewis, B. Gallagher, and B. Brown, “Cryogenic performance of the JWST primary mirror segment engineering development unit,” Proc. SPIE 8150, 815008, 815008-12 (2011).
[CrossRef]

S. B. Hutchison, A. Cochrane, S. McCord, and R. Bell, “Update status and capabilities for the LOTIS 6.5 meter collimator,” Proc. SPIE 7106, 710618, 710618-12 (2008).
[CrossRef]

Other (3)

E. Hecht, Optics, 4th ed. (Pearson Education, 2002), Chap. 10.

J. Goodman, Introduction to Fourier Optics, 3rd ed. (Roberts & Company Publishers, 2005), Chap. 4.

D. W. Kim and J. H. Burge, “cryogenic thermal mask for space-cold optical testing for space optical systems,” in OF&T, OSA Technical Digest Series (Optical Society of America), FTuS2 (2010).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (13)

Fig. 1
Fig. 1

Thermal plate with array of holes (left) and a conceptual cryogenic optical testing configuration using TS in a vacuum chamber (right) (Note: The red rays represent the thermal radiation from the collimator, and the black rays represent the collimated test beam.).

Fig. 2
Fig. 2

Schematic thermal transfer model with three thermal plates in a vacuum chamber. The solid arrows represent the net emissive power in each space. Also, as an example, four emissive power components contributing to Jnet_2- are depicted as dotted arrows 1-4. (1) Graybody radiation from the 2nd thermal plate, (2) Reflection of Jnet_2+ by the 2nd thermal plate, (3) Leak of Jnet_3- through the 2nd plate holes except the power directly passes through the 1st plate holes, and (4) Leak of Jnet_4- through the 3rd and 2nd plate holes except the power directly passes through the 1st plate holes.

Fig. 3
Fig. 3

Projected solid angle geometry between a hole at the bottom thermal plate and another hole at the top plate (S: spacing between the plates, I: interval between holes) for n = 2 and m = 1 case in Eq. (3).

Fig. 4
Fig. 4

Normalized intensity distribution of the complex fields at each thermal plate as the test beam passes through a hole-set.

Fig. 5
Fig. 5

x-profiles of the normalized intensity distribution of the test beam right before the 2nd and 3rd hole in the thermal plates (The shaded region represents the geometrical shadow region.).

Fig. 6
Fig. 6

Normalized Airy disk pattern (left), and the first nine diffraction orders at the focal plane of the optical system under test (right).

Fig. 7
Fig. 7

Comparison between the analytical thermal transfer model in Eq. (16) and the Zemax numerical simulation using non-sequential ray tracing (for T1 = 300K, T2 = 252K, T3 = 35K and ε1 = ε3 = 0.9, ε2 = 0.1 case).

Fig. 8
Fig. 8

Thermal loads as a function of the 2nd thermal plate’s temperature T2 for various emissivity values of the thermal plates (Note: T1 = 300K and T3 = 35K case).

Fig. 9
Fig. 9

Thermal analysis of system with T2 fixed at 252K: Thermal loads to the cold optical system space ΔJC (left) and the hot collimator space ΔJH (right) (Note: ε1 = ε3 = 0.9, ε2 = 0.1).

Fig. 10
Fig. 10

Thermal equilibrium temperature for the 2nd thermal plate allowed to float: T2 vs. T3 (left) and T1 (right) (Note: ε1 = ε3 = 0.9, ε2 = 0.1).

Fig. 11
Fig. 11

Thermal analysis of system with T2 allowed to float: Thermal loads to the cold optical system space ΔJC (left) and the hot collimator space ΔJH (right) (Note: ε1 = ε3 = 0.9, ε2 = 0.1).

Fig. 12
Fig. 12

Comparison between the ideal and distorted complex field at the last hole after the test beam went through a perfect hole-set and a perturbed hole-set, respectively. (Tolerance: δx = 50µm, δy = 50µm, and δDhole = 20µm).

Fig. 13
Fig. 13

Variations in the transmitted wavefront amplitude (left) and phase (right) due to variations in hole size and position.

Tables (2)

Tables Icon

Table 1 TS Design Parameter Values for a Hole-set Wave Propagation Simulation

Tables Icon

Table 2 Nominal TS Design Parameters

Equations (25)

Equations on this page are rendered with MathJax. Learn more.

J=εσ T 4 [W/ m 2 ]
J net_2 = ε 2 σ T 2 4 α:(1)inFig.2. + J net_2+ (1 ε 2 )α:(2)inFig.2. + J net_3 (π Ω eff1 ) π (1α):(3)inFig.2. + J net_4 ( Ω eff1 Ω eff2 ) π (1α):(4)inFig.2.
Ω eff1 π ( D hole /2) 2 S 2 (1+4 n=1 m=0 cos 4 θ) = π D hole 2 4 S 2 {1+4 n=1 m=0 ( S S 2 + I 2 ( n 2 + m 2 ) ) 4 }
Ω eff2 π ( D hole /2) 2 (2S) 2 (1+4 n=1 m=0 cos 4 θ) = π D hole 2 16 S 2 {1+4 n=1 m=0 ( S S 2 + I 2 ( n 2 + m 2 ) ) 4 }
D hole >2 λS 2 .
U(x,y)=A(x,y)exp(i 2π λ Φ(x,y))
U n ( x n , y n ) F η= y n λS F ξ= x n λS [ U p ( x p , y p )exp{ iπ λS ( x p 2 + y p 2 )}]
U focal (x,y) F η= y λ f eff F ξ= x λ f eff [ U TS (x,y)]
U TS (x,y)=cyl( x 2 + y 2 D TS ){ comb( x I , y I ) U hole (x,y) }
U focal (x,y) F η= y λ f eff F ξ= x λ f eff [cyl( x 2 + y 2 D TS ){comb( x I , y I ) U hole (x,y)}] = F η= y λ f eff F ξ= x λ f eff [cyl( x 2 + y 2 D TS )]** F η= y λ f eff F ξ= x λ f eff [comb( x I , y I )** U hole (x,y)] somb( D TS x 2 + y 2 λ f eff ){comb( Ix λ f eff , Iy λ f eff ) F η= y λ f eff F ξ= x λ f eff [ U hole (x,y)]}
Q focal_somb (x,y) | U focal_somb (x,y) | 2 = | somb( D TS x 2 + y 2 λ f eff ) | 2
D Airy 2.44λ f eff D TS
K= λ f eff I
D Airy 2.44λ f eff D system << λ f eff I =K
I<< D system 2.44
[ 1 0 0 0 0 0 0 0 ( ε 1 1)α 1 0 (α1) 0 Ω eff1 (α1)/π 0 Ω eff2 (α1)/π (π Ω eff1 )(α1)/π 0 1 ( ε 1 1)α 0 0 0 0 0 0 ( ε 2 1)α 1 0 (π Ω eff1 )(α1)/π 0 ( Ω eff1 Ω eff2 )(α1)/π ( Ω eff1 Ω eff2 )(α1)/π 0 (π Ω eff1 )(α1)/π 0 1 ( ε 2 1)α 0 0 0 0 0 0 ( ε 3 1)α 1 0 (π Ω eff1 )(α1)/π Ω eff2 (α1)/π 0 Ω eff1 (α1)/π 0 (α1) 0 1 ( ε 3 1)α 0 0 0 0 0 0 0 1 ][ J net_1+ J net_1 J net_2+ J net_2 J net_3+ J net_3 J net_4+ J net_4 ]=[ σ T H 4 σ ε 1 T 1 4 α σ ε 1 T 1 4 α σ ε 2 T 2 4 α σ ε 2 T 2 4 α σ ε 3 T 3 4 α σ ε 3 T 3 4 α σ T C 4 ]
Δ J C = J net_4+ J net_4
Δ J H = J net_1 J net_1+
Δ J 2 = J net_2+ + J net_3 J net_2 J net_3+ =0
Δ a = | hole U hole_perturbed (x,y) dxdy || hole U hole_perfect (x,y) dxdy | | hole U hole_perfect (x,y) dxdy | 100(%)
Δ p = Angle[ hole U hole_perturbed (x,y) dxdy]Angle[ hole U hole_perfect (x,y) dxdy] 2π (waves)
Δ i = ΔQ Q 1002 ΔA A 100=2 Δ a
cyl( x 2 + y 2 )={ 1 , x 2 + y 2 1/2 0 , x 2 + y 2 >1/2
somb( x 2 + y 2 )= 2 J 1 (π x 2 + y 2 ) π x 2 + y 2
comb(x,y)= m= n= δ(xm,yn)

Metrics