次世代観測装置用の新しい回折格子の開発状況	 II	 
海老塚	 	 昇昇1, 細畠	 	 拓拓也1, 山形	 	 豊豊1, 岡本隆之2, 佐藤	 	 慎慎也3,
田辺	 	 綾綾乃3, 橋本	 	 信信幸3, 佐々木	 	 実実4, 魚本	 幸	 幸5, 島津	 	 武武仁5,桐野	 	 宙宙治6, 尾崎	 	 忍忍夫7, 青木	 	 和和光7, 高見	 英	 英樹7	1理研	 先端光学素子開発チーム, 		3シチズンホールディングス	 (株) 開発部,
5東北大学	 学際科学フロンティア研究所,
7国立天文台	 光赤外研究部	

2理研	 石橋極微デバイス工学研究室,	

4豊田工業大学	 ナノテクプラットフォーム,
6(株) クリスタル光学	 開発部, 	

第5回
回可視赤外線観測装置技術ワークショップ		

2015年12月7-9日	 	 東北大学	 	

Spectrograph of 30m Telescope (R~ 50,000@1µµm)	

Slit width	

NaturalDiffraction
Remarks	

seeing: 0.5””	  limit: 0.0084”” 	

727µµm	12.2µµm	

Dcol		

3 m	

0.05 m	Fcol 	30 m	36 × 9 × 	

4.5 [m]	

0.5 m	

Camera F	

Precision of
optical elements 	

Size ofspectrograph	

F/10	

α = 26.7°,	

~ 900g/mm	

F/10	

F/0.62		

0.6 × 0.15 ×
0.075 [m]	F/37	15µµm × 3 pix.	

~ 3λλ	

< λ/20	r.m.s.	

A high dispersion grating is necessary!	

Littrowmount	Novel Gratings under Development	

P Volume phase holographic (VPH) grating ??@BFGSA=F<98:BE+-*-	,<=7>;E5G=A;B:F=AHFB=85?=A89K@B8H?5G=BA:BEG<9 FGBE89E8=::E57G=BA 	 =E9:E=A;9A79.( ;E5G=A;	.( ;E5G=A;B:J<=7<FC97GE5?9:S7=9A7L=F7B=A7=89J=G<+5A8(CB?5E=M5G=BA6LHF=A;
6=E9:E=A;9AG@98=5 	

P =E9:E=A;9A79E5;;6=A5EL;E5G=A;	

,<=7>E97G5A;H?5E;E5G=A;B:J<=7<FC97GE5?9:S7=9A7L=F7B=A7=89J=G<+5A8(CB?5E=M5G=BA
6LHF=A;6=E9:E=A;9AG@98=5 I5=?56?9:BEG<9 FG5A8F9I9E5?8=::E57G=BABE89E 	

P +HE:579E9?=9:;E5G=A;J=G<57HG95A;?9;EBBI9F	

*9C?=75G98grism:BE%'!*+J=G<<=;<=A89KCE=F@ E8NG<8=::E57G=BABE89E 	P )H5F=E5;;;E5G=A;	

,E5AF@=FF=BA;E5G=A;:BE<=;<8=::E57G=BABE89E:56E=75G986L?5@=A5G=BAB:@=EEBEC?5G9F 
5I=A;G<9=@5;=A;75C56=?=GL 	P Immersion grating ?E958L89I9?BC98=Aμ@65A8HA89E89I9?BC@9AG:BEG<9A95E

=A:E5E98）	

=;<8=FC9EF=BAechelle;E5G=A;B:J<=7<BCG=75?C5G<=FS??98HC5<=;<=A89K@98=5 	 )H5F=E5;;=@@9EF=BA;E5G=A;	

&2J20@6;:.:1(>.:?96??6;:>.@6:4	 	  -G=?=M9J=89E5A;99?97GEB@5;A9G=7
J5I9:EB@0E5LGB, M 	 *9?5G=I9?L=A9KC9AF=I9 	*9T97G=BA;E5G=A;	 

Transmission grating	  B??=@5GBE5A875@9E5BCG=7F7BH?8
C?579A95E6LG<9;E5G=A; 	

 !G=F56?9GBE98H79F=M9B:G<9spectro@9G9E 	

9I9?BC@9AGB:G<9GE5AF@=FF=BA;E5G=A;:BE<=;<9EBE89E
8=::E57G=BAJ=G<<=;<8=FC9EF=BA<5F699A89@5A898 	 3I062:062?;3(>.:?96??6;:>.@6:4?	

TEM mode	

TEM mode	+HE:579E9?=9:;E5G=A;	:S7=9A7L897E95F9F
FG99C?L69?BJΛ/λ	VPH (Volume Phase Holographic)
grating (ΔAN:S7=9A7L
increases up to 100%69?BJΛ/λ.	

'>59G 5? +(!)	

633>.0@6;:3I062:062?;3)$Grism for FOCAS��VPH grating 	; @@?5M9 A@Λ/λ *N  )	+HE:579E9?=9:;E5G=A;	

 ; @@?5M9 A@Λ/λ *N  )	

$;8.>6F21633>.0@6;:3I062:0E;3)$>.@6:4	' π (n − n ) t *maxmin
ηS = sin (+) Λ( n max + n min ) sin2θ ,2%95FHE98CB?5E=M988=::E57G=BA
9:S7=9A7=9FB:5CEBGBGLC9.( ;E5G=A;:BE5%'!*+grism  	n5I9 Λ μm t = 20 µm, 	θ  Oλ
µ@ 	' π ( n − n ) t cos2θ *maxmin
ηP = sin (+) Λ( n max + n min ) sin2θ ,2

5?7H?5G98CB?5E=M5G=BA8=::E57G=BA
9:S7=9A7=9FI9EFHFG<=7>A9FFB:5.( ;E5G=A;J=G<E9:E57G=I9=A89K
@B8H?5G=BAΔA 	[6=MH>59G5? (+", 636]	

6>23>6:42:02)$>.@6:4��

n Smax − n Smin(n − n Pmin ) cos2θ P= Pmax
(n Smax + n Smin )sin2θ S (n Pmax + n Pmin )sin2θ P

n Smax − n Smin(n Pmax − n Pmin ) cos2θ P=(n Smax + n Smin ) ⋅ 2sinθ S cosθ S =	 ( n Pmax + n Pmin ) ⋅ 2sinθP cosθ P+A9??RF?BJ	

n Smax − n Smin ( n Pmax − n Pmin ) cos2θ P≅
cos θ Scosθ P

5?7H?5G98CB?5E=M5G=BA8=::E57G=BA
9:S7=9A7=9FI9EFHF;E5G=A;G<=7>A9FFt
B:6=E9:E=A;9A79.( ;E5G=A; �Fabrication for Liquid Crystal Grating �(BJ9E@9G9E	   A@ 98$5F9E	 

B?8=A;
mirror	 5?:@=EEBE	 B?8=A;@=EEBE	 95@9KC5A89E	  B?8=A;
mirror	 B?8=A;@=EEBE	 *BG5G=A;<B?89E	 

Two beam interference exposure optics 	 Λ = mλ/2sinθB = 0.325/2sin 21.3° = 0.447 [μm] 	

(2,235 grooves/mm)	 	 

6=A61>E?@.8)$4>.@6:4��

!-$ %9E7>%"   -. @/  F97 	 !,#&%9E7>%"   -.@/  F97 	

696@.@6;:;3)$>.@6:4	

α =31.7 deg.	

Δn=0.10	Δn=0.07	

Δn=0.04	

Δn=0.02	

6th	3rd	10th	

α =30.9 deg.	

5A8J=8G<B:.( ;E5G=A;697B@9FA5EEBJin 8=::E57G=BA5A;?9α increase 6975HF9Femi5@C?=GH89B:=A89K@B8H?5G=BAΔAB:
8=7<EB@5G98;9?5G=A=FHCGB  	[5?8EL9G5? (+( 4	

=::E57G=BA9:S7=9A7LB:
.( ;E5G=A;897E95F9
GBJ5E8<=;<9EBE89EF 	3'>59G 5? +(!  ]	

MOIRCS SR Grism �Prism material 1	2A+9(n1   μm)	

Plate 			+(%A2    μm)	

(E=F@I9EG9K5A;?9 	α  O	!A7=89AG5A;?9		θ0O	EBBI96?5M95A;?9 	β O	

EBBI9I9EG9K5A;?9γ O	

E5G=A;C9E=B8		Λ μ@ ;EBBI9F @@	G<*  μmM65A8	G<*  μm165A8	G<*   μm"65A8	G<*  μm 65A8	E8*  μm#65A8	 O	*≦ μm� � OQ O�Diamond Bite for Master Grating�� O	Q O���Fabrication Method for MOIRCS SR Grating��

+<5C9E7HGG=A;B:@5FG9E;E5G=A;	

/BE> 		

：&=(5??BLB:&BA			

9?97GEB?LG=7C?5G=A;	

?5M95A;?9 	β O	

.9EG9K5A;?9 	γ O	

E5G=A;C9E=B8	Λ μm�

Substrate	 	 Clear resin	 	 

Master grating	 	 *9C?=75G=BA�

Finish�Limitation of Surface Relief Grating		

n sin(α -θ1) = sin(α θ0) 	

n (sinα cosθ1- sinθ1 cosα) 	

= sinα cosθ0  sinθ0 cosα	

(n cosθ1 - cosθ0) sinα 	= (sinθ0  n sinθ1) cosα 	= 2sinθ0 cosα 	tanα = 2sinθ0 / (n cosθ1 - cosθ0)	

Λ�sinθ0 = n sinθ1 	n sin(α -θ1) = sinθ2	θ2 = α θ0	θ0�α�θ1�α-θ1�n�A θ0 ≤O (θ2  O	A θ0 ≤O(θ2  O	=5@BA8A  A@	+HE:579E9?=9:;E5G=A;J=G<F5JGBBG<;EBBI9F=FABG:95F=6?9
:BEG<9@98=H@5A8<=;<E9F ;E5G=A;F �α� θ �θ0� 2Quasi-Bragg grating	%A.?6>.44>.@6:43;>6452>#>12>?	 )H5F=E5;;;E5G=A;)
57<=9I9F<=;<8=::E57G=BA
9:S7=9A7LGBJ5E8<=;<9EBE89E 	 )=A<9E=GF58I5AG5;9FB:.( ;E5G=A; 	

 )<5FG<9=@5;=A;CEBC9EGL 	

=::E57G=BA:S7=9A7LB:DH5F=
E5;;;E5G=A; A  Λ  μmG  μm, θ1 = θ2  O 	
3'>59G5? +(!  4	Quasi-Bragg Grism�

Quasi-Bragg
grating with silica �60��

Adhesive is available �ZnSe��ZnSe��
70��.=F=6?9 N
A@&95E!* N μm)	

+H6FGE5G9 		

+=?=75BCG=75?;?5FF9G7 	+=M9 × &B B:?5L9E50 × ×G × 350CF7 	

(9E=B8=79EEBE	N A@(. NA@rms)	

Trial Fabrication of Quasi-Bragg Grating 1	

A: 10 x 10 x 0.2 x 40 pcs (left),	

B: 1.5 x 10 x 0.2 x 40 pcs (right)	

Laminatingof Mirror
Plate	Cutting	

Lapping andPolishing	for WaveGuide	Diffraction by Quasi-Bragg Grating	
Normal incidence��

Small incident angle	

Ideal incident angle	

G<BE89E	

=::E57G=BA695@	Large incident angle	Au膜
膜を用いた大気中の原子拡散接合法�
合成石英ウエハ B	

Au (20 nm)/Ti(5 nm)

合成石英ウエハA	

(4 inch diameter)	

片側あたりAu(20 nm)/Ti(5 nm)のの膜厚で合成石英ウエハを接合した際の連続写真	◆	  重ねたウエハの一部をピンセット等で加圧すると，Au/Au界界面に再結晶の核が形成され，瞬時にウエハ全体に伝搬.	

◆ 真空中の接合でも同様であると推定. 	

TOHOKU
UNIVERSITY

Si substrate
Cr

Au/AuCrSi substrateoriginalsurface

20 nm

片側あたりAu(20 nm)/Cr(5 nm)のの膜厚でSiウウエハを接合した際の断面TEM写
写真	Trial Fabrication of Quasi-Bragg Grating 2	

$5@=A5G986L;B?8:HF=BA
in room temperature 	/=E9F5J7HGG=A; 	

F<99GFB:DH5EGM;?5FFFH6FGE5G9FB:φ25 × t G<5GG<9;B?889CBF=G986L
FCHGG9E=A;BA6BG<F=89F5E9FG57>986L5EBB@G9@C9E5GHE96BA8=A;(Tohoku-A=I9EF=GL+<=@58MH?56BE5GBEL 	 Thickness to t 6LJ=E9F5J7HGG=A; 	

 Thickness to t 6LCB?=F<=A; 	Trial Fabrication of Quasi-Bragg Grating 3�

Diffraction Images of Quasi-Bragg Gratings��
$5@=A5G986L58<9F=I9J=G<;?5FF6958F,E=5?:56E=75G=BA 	

$5@=A5G986L;B?8:HF=BA=AEBB@G9@C9E5GHE9,E=5?:56E=75G=BA 	

@6BFF98@=EEBEFH6FGE5G9F?5@=A5G986L58<9F=I9,E=5?:56E=75G=BA	Fabrication Method of Quasi-Bragg Grating��

+<5C9E7HGG=A;B:@5FG9E;E5G=A;
JBE>：&=(5??BLB:ABA
9?97GEB?LG=7C?5G=A;Λ Nμm,γ N O)�

,BCI=9J�
-CC9EFH6FGE5G9�
?95EE9F=A�
%9G5??=7@=EEBE�
*9C?=75G98;E5G=A;�
$BJ9EFH6FGE5G9�

EBAGI=9J�
'6?=DH9=BA5FF=FG98FC5GG9E=A;B:
=??=A;B:7?95EE9F=A=AGB;EBBI9F→ Finish�
metallic mirror (Al, GNA@ �

Quasi-Bragg grating for TMT WFOS 		

Item 		%98=H@*9F ?H9%98=H@*9F ?H9%98=H@*9F *98 	

=;<*9F ?H9 	=;<*9F *98	Λ [μm] ([g/mm])
	  	   	  	  	  θ 0�	θ0	O	O	 O	O	OΛ��γ��θ0�	 γ 	'E89E		 O 	

G<NG<		  O 	G<N G<		  O 	

G<NG<		 O 	

G<N G<		 O 	

G<N G<	Conclusions	P VPH grating 57<=9I9F<=;<8=::E57G=BA9:S7=9A7L5A8I9EF5G=?9:BE@B89E5G95A;H?5E8=FC9EF=BA:BEG<9 FG8=::E57G=BABE89E 	

P ,9FG:56E=75G=BAB:.( ;E5G=A;FJ=G<?=DH=87ELFG5?B:-.7HE56?9=F8BA96LHF=A;5GJB695@F=AG9E:9EB@9G9EB:5A-.?5F9E 	

P +HE:579E9?=9:;E5G=A;J=G<57HG95A;?9;EBBI9F:BE%'!*+grisms 5E9;B=A;GB:56E=75G9 	P )H5F=E5;;;E5G=A;J<=7<@=EEBEC?5G9F?5@=A5G986L;B?8:HF=BA=AEBB@G9@C9E5GHE9,B<B>H-A=I9EF=GL5A8 9@6BFF98@=EEBE
FH6FGE5G9F?5@=A5G986L58<9F=I9,5E9:95F=6?99I9A:BEechelle
FC97GEBF7BCLB:I=F=6?9J5I9?9A;G< 	Quasi-Bragg Immersion Grating� NOG=?G98)H5F=E5;;
;E5G=A;J=G<9BE+=�
%9G5??=7@=EEBE� +=	120 (9)�

	9+=�
+=  9)�

&95E!* 	 N μm)			

%5G9E=5?	

2A+9+=9G7 		+=M9×$5L9EF40× ×G ×300CF7 		(9E=B8=79EEBE45nm (P-V), 9nm (rms)	

%=8!* 	N μm)			

%5G9E=5?	

9, 8,99G7 		+=M9×$5L9EF120× ×G ×300CF7 		(9E=B8=79EEBE150nm (P-V), 30nm (rms)