Micro-Pulling Down-Grown Nd3+: (La1-x,Bax)F3-x
as New Vacuum Ultraviolet Scintillator andPotential Laser Material
Marilou M. Cadatal1,2, Y. Furukawa,Young-Seok Seo3, Toshihiro Tatsumi3, Minh
Hong Pham1,2, Carlito Ponseca Jr.1,2, Shingo Ono4, Elmer Estacio3, Yusuke
Furukawa3, Hidetoshi Murakami3, Yasushi Fujimoto3, Nobuhiko Sarukura1-3,
Masahiro Nakatsuka3, Kentaro Fukuda5, Rayko Simura5, Toshihisa Suyama6,Akira Yoshikawa5
Institute for Molecular Science (IMS)1The Graduate University for Advanced Studies2
Institute of Laser Engineering Osaka University3
Opto-electronics Laboratory Nagoya Institute of Technology4
Institute of Multidisciplinary Research for Advanced Materials, Tohoku
University5Tokuyama Corporation6

Next target: Shorter wavelength region
Deep ultraviolet (DUV) region(250-180 nm)
andVacuum ultraviolet (VUV) region(180 nm – 50 nm)
Next target Ce3+:LiCaAlF6 laser
VUV
100

VisibleUV
200

300

400

500

Wavelength

600

Infrared700 (nm)Suitable material for VUVscintillator andall solid – state VUV laser ?

Nd3+:LaF3 Emission in the VUV• Optical pumping

JOSA B 9, 1148 (1992)• Electron beam pumping

App. Phys. Lett. 46, 14 (1985)

Nd3+:LaF3 Emission in the VUVz Restricted tunability (170 – 175 nm)z Electron beam pumpingz All-solid-state VUV laser needed

Looks attractive but not so muchfollow-up workPurpose“Investigate
Nd3+: (La1-x,Bax)F3-x (x=0.1) grown by
Micro – PD method as new VUVscintillator and potential lasermaterial”

Growth of Nd3+:La(1-x)BaxF(3-x) (x=0.1) byMicro-Pulling Down Method
Micro-PD apparatus for fluoride crystal growth

Nd3+: La(1-x)BaxF(3-x) (x=0.1)
sample by Prof. Fukuda atTohoku University

Diameter: 2 mm

A. Yoshikawa, T. Satonaga, K. Kamada, H. Sato, M.
Nikl, N. Solovieva,T. Fukuda, J. Cryst. Growth 270,427 (2004)

Transmission Characteristics ofLa(1-x)BaxF(3-x) (x=0.1) and LaF3

% Transmittance100(La1-x,Bax)F3-x (x=0.1)

75

BaF250

LaF3250120

160
200240
Wavelength (nm)280Transmission Edges:
BaF2 : 134 nm(La1-x,Bax)F3-x : 160 nm

LaF3 : 180 nm

Fluorescence spectra ofNd3+:La(1-x)BaxF(3-x) (x=0.1) and Nd3+:LaF3
Fluorescence Intensity(x25, arb. units)

scattered excitation(a) Nd3+:La(1-x)BaxF(3-x)(x=0.1)

1.00(a)(b) Nd3+:LaF3

0.75

0.50

0.25

(b)

0.00
150

175

200

225

250

Wavelength (nm)275300VUV Fluorescence spectra ofNd3+:La(1-x)BaxF(3-x) (x=0.1) and Nd3+:LaF3

Fluorescence Intensity(x25, arb. units)

scattered excitation
(a)

1.00

(a) Nd3+:La(1-x)BaxF(3-x)(x=0.1)• Peak: 175 nm

0.75• FWHM: 12 nm

0.50(b) Nd3+:LaF3(b)0.25• Peak: 172 nm• FWHM: 8 nm

0.00
150

160

170180

Wavelength (nm)190200Fluorescence Intensity(arb. units)

IR Fluorescence spectra ofNd3+:La(1-x)BaxF(3-x) (x=0.1)

900

1000

1100

1200

Wavelength (nm)
Excitation wavelength: 800 nm
Peak: 1053 nm

1300

1400

Experiment: Set – up for Evaluating VUVFluorescence Lifetime of Nd3+:La(1-x)BaxF(3-x) (x=0.1)
Streak camera system

Specially designed streak camera system

Specially designed spectrometer

12

Experiment: Streak Camera Image ofNd3+:LaF3 Fluorescence

157-nm excitation

172-nm fluorescenceFirst VUV streak camera image

13

Experiment: Nd3+:(La1-xBaxF3-x) (x=0.1)
and Nd3+:LaF3 Temporal Profile
13+Intensity (arb. units)

Nd :(La0.9Ba0.1F2.9) τ = 6.1(6) ns
Nd :LaF3 τ = 8.9(1) ns
3+

F2 laser ∆ t = 5ns

0.1

0.01

-100102030

405060Time (ns)Nd3+:(La1-x,Bax)F3-x (x=0.1) fluorescence decays faster14

Summary• Nd3+:(La1-x,Bax)F3-x (x = 1) single crystal is successfullygrown using the micro-Pulling Down method.
• Undoped Nd3+:(La1-x,Bax)F3-x (x = 1) sample has shorttransmission edge at 160 nm compared to LaF3 at 180 nm.
• Strong VUV fluorescence with peak located at 175 nm.
• Broad VUV fluorescence with FWHM of 12 nm comparedto Nd3+:LaF3 with FWHM of 8 nm.
[1] M. Cadatal.et al, J. Appl. Phys., 46 (2007) L985 - L987.
[2] M. Cadatal,et al, J. Opt. Soc. Am. B in press