9 Z 4, pp. 1013∼1017
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ç
¡ ¬ £ · T ç ¡ G B
ô
Çz @ / < Æ § F g Ó ü t o < Æõ , @ / 306-791 (2010¸ 6 Z 4 4{ 9 ~ Ã Î6 £ §, 2010¸ 9 Z 4 14{ 9 > F S X & ñ )
ç
ß [ O Z O ` ¦ 6 x K " f È Òõ % ò % i q ∆ s ; ¤ _ ì r à º » 1 Ï Ð © ` ¦ ì r$ 3 ô Ç . x ¸ ç ß [ O Á º ]
( РÒ' 8 £ ¤& ñ ) a ì r à º» 1 Ï Ð © _ 0 A © ì r í H á ÔY U3 A q-v Ø Ôy ñá Ô r] X & h ì rd \ H ô Ç \ V8 £ ¤ õ ¸ ú { 9 u
< Ê` ¦ Ð# ï r . ∆ = 1/2õ 1/3{ 9 M : s ; ¤ _ í H Ã º 0 A © © É r s ì r í\ ¦ s ê r . Õ ª Q
∆ 1/3 Ð t , í H Ã º 0 A © © [ þ t É r s ì r í\ " f © { © y # Á # Q " f × æ 0 A © ì r í\ ¦
· p . : rë H \ " f Ä » ¸ ) a s ; ¤ _ ì r à º » 1 Ï Ð © \ @ /ô Ç 1 l x < Êà º H © F g [ þ t _ 2 à º
\ ¦ & ñ _ H X < 6 x| ¨ c à º e .
Ù þ
d # Q: s , ; ¤ , » 1 Ï Ð´ òõ , ì r à º» 1 Ï Ð´ òõ
Interferometric Analyses of Fractional Talbot Images of Binary Amplitude Gratings with Different Opening Ratios
S. Chang ∗ · S. I. Lee
Department of Physics, Hannam University, Taejon 306-791 (Received 4 June, 2010 : accepted 14 September, 2010)
We use an interferometric method to analyze the fractional Talbot image of a binary amplitude grating with an opening ratio of ∆. The local phase variations of the imaging fields, which can be determined from Fizeau interferograms, are shown to be in good agreement with theoretical predictions based on a Fresnel-Kirchhoff diffraction integral. In the cases of ∆ = 1/2 and 1/3, pure phase images of binary amplitude gratings show binary structures. However, when the opening ratio is reduced to less than 1/3, the pure phase images are found to be substantially distorted, so they appear to have multilevel structures. The wave function of a fractional Talbot image derived here can be used to define quadric wavefront aberrations of imaging rays.
PACS numbers: 42.30.M
Keywords: Binary grating, Amplitude grating, Talbot effect, Fractional Talbot effect
I. " e  ] Ø
þ j H \ Ä ºo H F g F g < Æ& h ] X HZ O ` ¦ 6 x K " f Å Òl & h
½ ¨ ¸\ ¦ ; ¤ _ » 1 Ï Ð © (Talbot image)\ @ / ô
Ç © 7 á x s 1 l x à º x 9 ý a³ ð_ ¦ ½ Ó` ¦ í < Ê
∗
E-mail: [email protected]
H Ã º _ % ò ¾ Ó` ¦ ¸ % i ¦ [1–5], È Òõ % ò % i _ q
∆ = 1/2 s ; ¤ _ ì r à º » 1 Ï Ð © (fractional Talbot image) \ @ /ô Ç ¦ à º < Êà º\ ¦ Ä » ¸ô Ç e
[6]. » 1 Ï Ð © ¢ ¸ H ì r à º » 1 Ï Ð © s ê ø Í © λ ç ß [ O
F g` ¦ l : r Å Òl p ; ¤ \ q Æ Ò , á ÔY U3 A q r ] X
\ _ K " f (2p
2/λ) _ & ñ à º ¢ ¸ H ì r à º C \ K { © H o
\ " f \ ¦ ² ú © É r ; ¤ ¢ ¸ H 0 A © ì r í + þ A$ í ÷ & H & ³
-1013-
© ` ¦ { 9 ( H . à Р¦ë H ³ [6]\ " f Ä » ¸ ) a à º < Êà º H ì r Ã
º » 1 Ï Ð © \ p u H Ä »ô ÇF g _ % ò ¾ Ó` ¦ ì ø Í% ò l M :ë H
\
s 0 A © _ ì r à º » 1 Ï Ð © ` ¦ s 6 x ô Ç C \ P ¸" î
© u (array illuminator) [7,8]_ ¨ î \ 6 x| ¨ c à º e .
Õ
ª Q þ j H _ C \ P ¸" î © u \ " f · ú » ¡ ¤ q 1/2 Ð ± ú
É
r s ; ¤ ì r í\ ¦ % 3 l 0 Aô Ç ~ ½ ÓZ O Ü ¼ Ð × æ 0 A ©
_ 6 x s ] jî ß ÷ &% 3 [9–14]. s M :ë H \ È Òõ % ò % i _ q
1/2 Ð É r s _ ì r à º » 1 Ï Ð © ` ¦ ¨ î
9 , ý a³ ð_ ¦ ½ Ó @ / \ 2 ½ Ó t í < Ê
H Ã º \ ¦ D h\ v > & ñ _ K ô Ç . s \ ¦ 0 AK " f $ È
Òõ % ò % i _ q É r s ; ¤ \ ¦ ] j ô Ç Ê ê, ì r Ã
º » 1 Ï Ð o \ " f © _ 0 A © ì r í\ ¦ f ] X ' a ¹ 1 Ï ¦, Õ ª
õ \ ¦ [ O " î ½ + É Ã º e H & h ] X ô Ç 1 l x < ÊÃ º\ ¦ ¹ 1 Ô è q 9 כ ¹
e .
: r 7 Hë H \ " f Ä ºo H $ y F gÓ ü t| 9 s ¶ n s É r Ä »o \
d y Z O Ü ¼ Ð l : r Å Òl p = 900 µms ¦, È Òõ % ò
%
i _ q y y ∆ = 1/2, 1/3, 1/4, 1/5 x 9 1/6s ÷ & ¸ 2
¤ s ; ¤ \ ¦ ] j % i . s \ © λ = 633 nm _ ó ¡ µ ¢ §- W 1 : r Y Us $ F g` ¦ q ð r 6 £ §, (2p
2/λ)(s +
∆/2) _ o (é ß , s H & ñ Ã º e )\ Z ~ © \ " f = G t y 1.12
◦ á Ôo 7 £ §` ¦ : x K " f Ï ã J] X ) a ç H{ 9 ô Ç F g` ¦ × æ^ o ?r ( Ü
¼ Ð+ x ¸(Fizeau) ç ß [ O Á º] (\ ¦ % 3 % 3 . ç ß [ O Á º] (_ Â Ò ì
r s 1 l x É r ì r à º » 1 Ï Ð © _ 0 A © ì r í\ ¦ ì ø Í% ò l M :ë H \ s
\ ¦ : x K " f ì r à º » 1 Ï Ð © _ × æ 0 A © ì r í\ ¦ · ú · p Ê
ê, á ÔY U3 A q-v Ø Ôy ñá Ô & h ì r [15] Ü ¼ Ð > í ß ô Ç õ ü < q
§ % i .
II. Ä Z Ø ¤ ´ o| º V ê s8 ý Ò Þ] K ¤ ¤
Figure 1 É r l : r Å Òl p s ; ¤ _ ì r à º » 1 Ï
Ð © ` ¦ ' a ¹ 1 Ï l 0 Aô Ç © u _ > h| Ä Ì ¸s . _ È Òõ
% ò
% i q H ∆ = 1/M Ü ¼ Ð Å Ò# Qt 9, M É r & ñ Ã ºs .
© λ = 633 nm ¨ î ' ô Ç F g s s ; ¤ \ ¦ q Æ
Ò , \ ¦ : x õ ô Ç F g É r r] X Ã º\ " f # Q > h _
F g Ü ¼ Ð ° ú . r] X ) a F g [ þ t É r ì r à º » 1 Ï Ð o (2p
2/λ)(s + N/2M ) \ Z ~ \ " f ; ¤ É r ç H{ 9 ¦, 0 A
© s \ ¦ ² ú ª É r ì r í\ ¦ ë ß H [11–14]. # l " f s H & ñ Ã
ºs 9, & ñ Ã º Nõ M É r / B N Ã º\ ¦ ° ú t · ú § ô Ç . Õ ª
6 £ §, = G t y s 1.12
◦ · û ª É r á Ôo 7 £ §` ¦ : x K " f Ï ã J] X ) a ç H { 9
ô Ç F g ` ¦ ì r à º » 1 Ï Ð © õ × æ^ o ?r v , © _ 0 A © ì r
í\ ¦ ì ø Í% ò H x ¸ ç ß [ O Á º] ( Ò q t$ í ) a . f y ý a³ ð> _
" é ¶& h ` ¦ 0 A\ ¿ º ¦, xy ` ¦ õ { 9 u r v
Fig. 1. An optical setup for detecting the phase-type image of a binary amplitude grating with an opening ratio of ∆. A collimated light of wavelength λ illuminates the grating of period p. The light passing through the openings in the grating generates a phase-type image at a fractional Talbot distance ζ = (2p
2/λ)(s + ∆/2), where s is any integer. A reference beam refracted through a wedge prism is superimposed onto the phase-type image, so that the phase variation in the image can be recorded as a Fizeau interferogram.
Fig. 2. Transmission coefficient of a binary amplitude grating with an opening ratio of ∆ which is plotted as a function of position y.
, È Òõ % ò % i q ∆s ¦, y» ¡ ¤ ~ ½ Ó ¾ ÓÜ ¼ Ð 1 l x H s
; ¤ _ È Òõ < ÊÃ º(Fig. 2) H
τ (y) = 1, n − ∆/2 < y/p < n + ∆/2 0, n + ∆/2 < y/p < n + 1 − ∆/2
=
∞
X
m=−∞
a
mexp
i 2πm
p y
(1)
ü
< ° ú s è q à º e . 0 Ad \ " f n É r & ñ à ºs 9, i =
√ −1 s ¦, É Òo \ > Ã º H
a
m=
∆ , m = 0
sin(mπ∆)/(mπ), m 6= 0 (2) s
. d (2)\ " f m∆ 0s & ñ Ã ºs a
m= 0 s
H & h ` ¦ Å Ò3 l q ½ + É 9 כ ¹ e .
s
] j _ ß ¼l ì r à º » 1 Ï Ð o \ q K " f B Ä º
, ì r à º » 1 Ï Ð © _ ; ¤ < Êà º H á ÔY U3 A q-v Ø Ôy ñá Ô r
] X
& h ì r _ ý a³ ð\ ' a ô Ç 2 H d Ü ¼ Ð è q Ã
º e [15].
ψ(ξ, η
0, ζ) ∼ = C X
m
Z Z
A
dxdya
mexp
i 2πm
p y
× exp
iπ (x − ξ)
2+ (y − η
0)
2λζ
(3)
0
Ad \ " f C H & h ì r à º\ Á º ' a ô Ç © à ºs 9, (ξ, η
0, ζ) H
'
a ¹ 1 Ï 9 H 0 A_ ý a³ ðs . _ ß ¼l A Å Òl p\ q
K " f Ø æì r y ß ¼ , d (3)_ & h ì r É r
ψ(ξ, η
0, ζ) ∼ =
mA
X
m=−mA
a
mexp
−i πm
2λ p
2ζ
exp
i 2πm
p η
0(4)
s
) a [6]. # l " f m\ Á º ' a ô Ç © à º ½ Ó É r Ò q t| Ä Ì÷ &% 3 Ü ¼ 9, m
A H é ß Ã º(cut-off order) Ð" f _ ß ¼l \ _ > r ô
Ç . s ] j ' a ¹ 1 Ï ` ¦ : £ ¤& ñ ô Ç ì r à º » 1 Ï Ð o ζ = 2p
2λ
s + ∆
2
(5)
\
Z ~ H , d (4) H
ψ(ξ, η
0, ζ) ∼ =
mA
X
m=−mA