高精度２次元面偏光分光装置に用いる矩形ファイバーリボンの特性評価"EÄ¼, Ä½ , &ÄJ, mpÄxÄ(/7c)),n~Ä(²69), H. Lin (ęĪĄ69)

SOLAR-Cにおける彩層偏光分光観測:
光ファイバー束による面分光•!

vl8º|h×SOLAR-CØ
619:<k°¶
SOLAR UV-Vis-IR Telescope (SUVIT)!"#$!"%&'()*+,&),'-)%*(.(&),'(!"0"-&034%*(.(&),'(

5,)1.%'.16(%'1)718(,9%!"0"-&034%*(.(&),'(/0+12%*(.(&),'(•!

ĒĄėģĔĊò4!çþLDóV2āÃ­òÕÝì2vò'PåéÚÔ! ĐħĔĕîôªOîßñÚ! eÕĐħĔĕúy· ûĐĨĭĝĔĕóîj0|òfò¸ äÿéKčăĜĂĄĚĭħĠī
čăĮĊĦĔĖ:40µmx10µmĊĦĔĖ%: 1µm~9”

2D array of the fiber
array at the entrance

Converted into 3 1D-slits
at the exit
2

SOLAR-C SUVIT 偏光分光観測装置 (SP)
Reimgaging lens (focus adjustment)
f = 1414.4 (F/23.57)
Scan mirrorDetector

300

200

Spectrum mask
400

folding mirror

200

Relay lens(x1.5 magnification)

PBS

Folding mirror (fixed)
Filter wheel

Slit/IFU
Littrow mirror(offset aspheric)

Grating
814.4

•!

Spatial resolution
–!
–!

•!

45

<0.2” sampling for chromospheric lines<0.1” sampling for photospheric lines

Integral Field Unit (IFU)

Spectral resolution
–!
–!

•!

720

Chromospheric line: "/#" > 1x105 ( #V< 2km/s)
Photospheric line: "/#" > 2x105 ( #V< 1.5km/s)

24.6 mm

25Wavelength coverage–!
–!

Chromospheric line: He I 1083 nm & Ca II 854 nm
Photospheric line: Fe I 525 nm (or Fe I 630 nm)

22.5

22.53

Conﬁguration of the focal plane
Exit of the focal plane

Entrance of the focal plane
slit

slit
1.512 mm x 16 ribbons = 24.192 mm

1.5 mm

1.5 mmIFU

32 µm
28 µm2 µm

2 µm

3 slitsIFUÞþĐħĔĕ4

偏光分光装置で得られるデータĐħĔĕÞþĐĞĊĕĨHe I 1083 nmIFUÞþĐĞĊĕĨCa II 854 nm

2K

2K
Slit & IFU are switched by changing the camera read-out area.

5偏光分光装置の観測波長範囲
Spectral window corresponding
to 220pix on the detector

He I 1083.0 nm

Ca II 854.2 nm

Fe I 525.0 nm

Sampling

# of pixels

Wavelength range

He I 1083.0 nm

45.2 mÅ

220 pixels

1082.50 – 1083.49 nm (0.99 nm)

Ca II 854.2 nm

35.6 mÅ

220 pixels

853.72 – 854.50 nm (0.78 nm)Fe I 525.0 nm

21.9 mÅ

220 pixels

524.65 – 525.13 nm (0.48 nm)6

ファイバーリボンの検証
ęĪĄ69(H. Lin)Þ¸ åéKčăā1vò³äèéĜĂĄĚĭħĠī(odôğąČĄ´ćĦĐ)āÚíÕ¿õóRòQñ óÁār¡•!

core + cladding
40 $m
core 38 $m
core 8 $mĎĄđû³óH
1.3mm

–! Does they have enough accuracy forconstructing a 2D array?

•!

@óFÕěĭĤF–! Critical for the design of the spectrograph•!

core +cladding
10 $m

ĊĩĐĕĭĊ
–! Does the thin cladding work for "~1$m?

•!

Z
–! Because we have an pol analyzer after theIFU.

•!
•!

ĜĂĄĚĭó`ZeIĬa@T40$m
7顕微鏡によるファイバーサイズ・配列精度検証•!

Accuracy of the size and the alignment of asingle fiber ribbon.
–! The size of the elemental fiber is 10µm%43µm withless variability.
–! Though there are 2–3 µm offsets in the longer
direction of the rectangles at some fiber elements,
the straightness is well within acceptable level.

•!

There are slightly dark portions, but the transmission uniformity is within theacceptable level.

Ìファイバー出射光プロファイルの測定

Lamp

Stop(5-10 mm)Pin hole(100 !m)camera lensInterference filter(900 nm, 633 nm, 500 nm)BW 10 nm~170 mm

input F~100 mm

~170 mm

L ~ 100 – 150 mm
fiber sample

output F

camera(There is an uncertainty ofthe detector position inside~10 – 20 mm the camera.)

9

出射光プロファイル(λ=500nm, Input F=20)x2
fiber ribbon orientation

x1

Horizontal cut

x1
x2

core + cladding
40 !m
core 38 !mcore 8 !mcore +cladding
10 !m

Vertical cut

FWHM
FWQM

•! F~10-20 for the L~100 mm sample and F~ 4-9 for the L~150 mm sample.
•! Vertical stripes (parallel to the ribbon) are clearly seen for the short sample.

10

出射光プロファイル (λ=900nm, Input F=20)x2
fiber ribbon orientation

x1

Horizontal cut

x1
x2

core + cladding
40 !m
core 38 !mcore 8 !mcore +cladding
10 !m

Vertical cut

FWHM
FWQM

•! Not only the vertical stripes but also the horizontal stripes appear at thelonger wavelengths.

11

ファイバー出口の光量分布
Lamp

Pin hole(100 !m)lens

Interference filter(1100nm, 1000nm,900 nm,633 nm, 500 nm, BW 10nm)

500 nm F=17.5 fiber sample•!

input F

350 mm

633 nm F=17.5 

camera lens

The camera position isadjusted to have focus atthe exit of the fiber ribbon.

camera

900 nm F=17.5 1000 nm F=17.5 •! At the visible wavelengths ("~500 - 633 nm), the cores of the ribbon are uniformlyilluminated.
•! At the longer wavelengths ("~900 - 1100 nm), the cores are not uniformly illuminated. Somepatterns (fringing?) are seen dependent on the wavelength. The patterns at the exit of thefiber are probably related with the vertical stripes. K§e,!ÔďīċĨĥĭĖ

K·§e,! ĢĨēĥĭĖ12

偏光保持性能測定-¦y·q

4£|=
fiber


Glan-Taylor
Sample filber
shutter prism

spectrograph

spectrograph

Ocean Photonics
OP-Maya2000ProHC

fiber

lamp

WP-ÍÓÎÏÏÎÒ|=ÅÊÈÈÇÉÉÈÈÈÑÐÆÔfiber

Glan-Taylor
prism

Glan-Taylor
Sample filber
shutter prism

WP-

-¦y·q
Glan-Taylor
prism

WP-

Astropribor, APSAW
ret ~ 127deg. over 500 – 1100nm fiber

lamp

13

straight

bend

Bend & twist

14ĜĂĄĚĭā\ (Bendóø)

ĜĂĄĚĭā\ (bend+twist)

y·ĜĂĄĚĭÞÚ3*

偏光変調測定y·q Bend

Bend &Twist
Good modulation only when
the bend is applied

The modulation amplitude is slightly degradedwhen the bend + twist are applied.

15

Mueller行列測定
Bend

Ideal Mueller matrix
" Iout % "1' $$Q$ out ' = $0$U out ' $0' $$# Vout & #00
1000 0 %" Iin %'$ '0 0 '$ Qin 'x x '$U in ''$ 'x x &# Vin &-U-QGood preservation of thelinear polarization (Q).

+U

+Q

y·
ÉË観測された振る舞いの定性的な解釈•! =Tòô·eKā _çþó×ĥĭĖóvbØî µîßþÖ–! §e,ôďīċĨĥĭĖ
–! ·§e,ôĢĨēĥĭĖ•! gþäóĤĦāëíÚþóôvóĥĭĖ•! y·!ÃvĥĭĖ÷î5bóĥĭĖÞîßþ ! ·eKsòÞ _•! ·y·!ĥĭĖóbÞBñÚ (ďīċĨĥĭĖò©Ú)!·eKóĤĦÞ6ßÚ–! ĜĂĄĚĭÞ·Ú(ÙþÚô¬òiâÞÙþ)öðĥĭĖ¹óz*Þ¤ßûçàÕÃvóĥĭĖòúĆĘĨĉĭÞà•! Z–! G9ñ¾eTîCYTāZéèþÖ–! Zò ÚíÚþóôvóĥĭĖêĀÛ (ÃvĥĭĖòô¾eTÞ ßòàÚ)•! y·!ÃvĥĭĖ÷î5bóĥĭĖÞîßþ ! ZTôUÚ•! ·y·!vĥĭĖÞ$¥ ! ZTôüÚ–! ãó3*ÕčăĎĄđāAäàçþïÕ+æy·îúvĥĭĖÞ$¥åûçÚ,òñþéùÕZTôüàñþï^|äÿþÖ•!

ĥĭĖbÞBñÚ(vĥĭĖÞ$¥åíÚþ)3*ÕóÿeÕiâĩĐÕ±óCY(«®)óĤĦñðóMÀā(áûçÚ(ÝúåÿñÚ)Ö
17クロストーク(漏れ出し)測定ĜĂĄĚĭõó@ĝĩĜĂĄĨ|=LampStop(5-15 mm)Pin hole(!5 $m)camera lensInterference filter
BP 10 nm~185 mm

~200 mm

~260 mmcamera•! ĊĦĔĖ%ÞÚ(1$m)éùÕòy·Þ·Ú3*òÞ}ÿê
çãïÞWSäÿéÖ•! ĜĂĄĚĭõó@ĝĩĜĂĄĨïĜĂĄĚĭÝýó@ĝĩĜĂĄĨāw¨çþãïî»]çþĜĂĄĚĭčăòÞ}ÿåíÚþ
Ýā|=ÖĜĂĄĚĭÝýó@ĝĩĜĂĄĨ|=Lamp

Pin hole(!5 $m)Stop(5-15 mm)camera lenscamera lensInterference filter
BP 10 nm~185 mm

~200 mmfiber sample(straight, L=100 mm)camera~260 mm18

500 nmInput

Output(F/18.5)

Input

OutputInput

Output(F/18.5)(F/18.5)

800 nm

600 nmInput

Output

1000nm(F/18.5)

19

•! The size of the output beam
monotonically increases as afunction of the wavelength.
–! The degradation of the beam size is not
so significant in the visible wavelength
range (500 nm, 580 nm, and 633 nm).

ĐġĔĕĎĄđクロストーク(漏れ出し)測定–! The degradation becomes significant in
the IR wavelength range (800 nm, 900nm, and 1000 nm), which indicatessignificant leakage to adjacent fibers(crosstalk) at these wavelengths.
–! When the F-ratio of the incident beam isslow (F>30), the crosstalk becomes small.

y·
Penetration of the Evanescent wave into the cladding

E = E 0 exp "x / x g()

The penetration depth xg can be expressed as below:xg "1n1k0 sin 2 # c $ sin 2 # m=%2& n12 cos2 # m $ n 22

sin # c = n12 $ n 22 n1 = 2'
k0 = 2& %20

まとめ•! SOLAR-CÃH2v¿õóRā[åéKčăĜĂĄĚĭóT¢–! ĎĄđĬ³ ! OK–! @ ! F (focal ratio degradation)ôOKÕéêåÕgþäóĤĦòìÚíô
|õóMÀû;=Tār¡çþQÞÙþ–! Z ! bendêáñýOKÖĆġĈďtî.=åé3*óMÀ¢–! ĊĩĐĕĭĊ ! y·1 $mîNGÖĊĦĔĖā%àçþñðåí?R•!

Nó=–! ĜĂĄĚĭħĠīāĆġĈďtî.=åé
>ÂuòüþT¢(iâòüþ@ĝĩĜĂĄĨó4#ÕĆġĈď.#RÞZòÜþMÀ)–! ¹ Ĭy· ¯XóéùÕ
KčăóA1# (40 $m ! 30 $m)ĊĩĐĕĭĊó{21