FIR UF

Research Center for Development of Far-Infrared Region, University of Fukui

Univ. Fukui

福井大学

遠赤外領域開発研究センター

About FIR UF■The Research Center for Development of Far-Infrared Region at the University of

Fukui (FIR UF, or FIR Center) is performing research and development in the
far-infrared region between radiofrequency waves and visible light using worldclass gyrotrons, which were originally developed at the FIR UF.
■The FIR UF attracts a great deal of attention owing to its contribution to theglobal evolution of the research and development in the far-infrared region
through the Center’s agreements for academic exchanges and memorandums

Director

Prof. Masahiko Tani

of understanding (MOUs) for collaborations with numerous domestic andoverseas institutions.

Overview of FIR UF
The far-infrared (FIR), i.e., terahertz (THz), frequency region is between the radiofrequency (RF) wave region andthe infrared light region. The wavelengths of the FIR region range from a few mm to a few tens of micrometers,roughly corresponding to a frequency range of 100 GHz to 10 THz. The electromagnetic (EM) waves in the FIR/THz
wave region can propagate in straight lines as light waves and penetrate materials as RF waves. This wavelength
region is proving invaluable for many essential 21st-century technologies.
The FIR/THz wave region has long been regarded as an unexplored region because of the lack of powerfulsources.Rapid and great progress is expected regarding the FIR region in the very near future. The FIR UF hasdeveloped a novel high power far-infrared source “Gyrotron” and is conducting the research and development of
new technologies using these world-class machines. The FIR UF is also performing research on THz science,developing novel methods of THz wave generation and new THz spectroscopic techniques. The FIR UF is now aleading research base for FIR/THz waves in Japan.
The FIR UF collaborates with domestic and overseas institutions in worldwide research activities. The center
aims to fulfill its role as a world-class base for research on FIR/THz waves. Their research on high-frequency
gyrotrons and the development of new FIR/THz spectroscopic techniques attracts considerable attention fromaround the world.

The electromagnetic spectrum

1About FIR UF

Objectivesand
Researchof Research
Development
and Development
Objectives in in
FIR
FIR
UFFU
To investigate the unexplored region of EM waves●Further improvement of our high-power FIR/THz-wave-source gyrotrons●Development of basic technologies in the FIR region, such as high-efficiency power transmission systems and high-sensitivity detectors
To extend research fields with our FIR/THz gyrotrons●Application of FIR/THz gyrotrons to fundamental physics, materials
science, life science, the development of materials with new functions,energy science, and many other fields
To develop novel methods of THz wave generation, detection, and propagation●THz optical and spectroscopic research using broadband THz waves
To open a new academic field

An advanced gyrotron●Aiming to open a new and interdisciplinary academic field in FIR/THz
regions associated with fundamental physics, material science, energy
science, life science, etc. using high-power FIR/THz radiation sources

Chronology of FIR UF
Early 1980’s

Research for FIR/THz region begins.

1984 Successful oscillations at 70 GHz and 100 GHz by Gyrotron FU I,
attracting worldwide attention as a high-frequency gyrotron
1989 Realization of sub-millimeter wave gyrotron at 380 GHz
1991 Gyrotron oscillations at 636 GHz
1992 The Laboratory for Application of Superconducting Magnets is founded in the Faculty of Engineering.

Gyrotron FU I

1996 Gyrotron oscillations at 837 GHz
1997 Gyrotron oscillations at 889 GHz (world’s highest-frequency gyrotron
oscillations)

An advanced gyrotron

1999 The FIR Center is founded by the re-organization of the Laboratory
for Application of Superconducting Magnets in Faculty of Engineering
per the ordinance of the Ministry of Education.
2005 World’s first gyrotron oscillations exceeding 1 THz (1013 GHz)
2006 The Cryogenic Laboratory is functionally integrated into the FIR
Center.
2008 Research for THz science begins.
2011

Joint research scheme, open to public, begins.

2013 Research for FIR/THz region in University of Fukui is designated by
the Ministry of Education as one of the research topics that must be

Displayed in the entrance hall of
FIR UF building

performed intensively.

2

Research organization

Research organization● Director: Prof. Masahiko Tani

● Research Supervisor: Prof. Teruo Saito● Vice Director: Prof. Seitaro Mitsudo● Supervisor of International Cooperation: Prof. Toshitaka Idehara

Research groups of FIR UF
Core research group 1.

Attach the domain name “u-fukui.ac.jp”,
after “@” of the following to form the full e-mail addresses.

Development of fundamental far-infrared technologies
Prof. Teruo Saito, Associate Prof. Yoshinori Tatematsu.
Postdoctoral fellows: Dr. Yusuke Yamaguchi, Dr. Eduard M. Khutoryan● Development of high-power far-infrared radiation sources● Research into the high-efficiency, high-stability,and high-frequency operation of gyrotrons▲▲▲

P5 , 6E-mail:saitot@
tatema@Core research group 2.

Applications of THz technologies for research in materials science and sensing
Prof. Masahiko Tani, Associate Prof. Kohji Yamamoto.
Postdoctoral fellows: Dr. Atsushi Iwamae, Dr. Gudrun Niehues, Dr. Stefan Funkner● Development and application of novel THz-wave emitters anddetectors● THz optical and spectroscopic research using broadband THz

waves● Time-domain coherent anti-Stokes Raman scattering (CARS)

spectroscopy in the THz region▲▲▲

P9 , 10E-mail:tani@kohji@
Core research group 3.

Development of new technologies in the far-infrared region

Prof. Isamu Ogawa● Further improvements in the gyrotron performance for application as a high-power far-infrared radiation source● Development of high-performance transmission lines for wider application of

the gyrotrons▲▲▲

P5 , 6E-mail:ogawa@Core research group 4.

Low-temperature and condensed-matter physics in the far-infrared region

Prof. Seitaro Mitsudo, Associate Prof. Yutaka Fujii● Electron spin resonance spectroscopy in the submillimeter-wave region● Millimeter- and submillimeter-wave material processing● Development and application of dynamic nuclear polarization-enhanced nuclear magnetic resonance (DNP-NMR)

▲
▲
▲

3

P7, 8

E-mail:mitsudo@
yfujii@Research organization

International cooperative research group 1.

Development of high-power THz-wave technologies

Prof. Toshitaka Idehara● Development of high-power THz-wave radiation sources: the Gyrotron FU

CW Series● Development of new THz technologies through international collaborations▲▲▲

P5 , 7, 8

E-mail:idehara@

Visiting professor's group 1.

Far-infrared spectroscopy and its applications

Prof. Seizi Nishizawa, Prof. Shintaro Ishiyama, Prof. Yoshiaki Tsunawaki, Associate Prof. Mitsuru Toda
● Applications of high-power THz waves● Development and applications of novel THz time-domain spectroscopy (TDS)

Visiting professor's group 2.

Development of far-infrared devices

Prof. M.Petelin, Prof. G.N.C.Santos, Prof. H.Aripin, Prof. V.N.Manuilov● Development of submillimeter-wave gyrotrons for materials processing● Computer simulation for the design of gyro devices

Cooperative research group 1.

Material physics in the far-infrared region

Prof. Hikomitsu Kikuchi, Prof. Kazutoshi Fukui● Electron spin resonance (ESR) spectroscopy in the submillimeter wavelength range● Studies of the optical properties of nitride semiconductors using broadband spectroscopy

in the far infrared to vacuum ultraviolet range

Cooperative research group 2.

Applications of far-infrared lasers

Prof. Toshikazu Hori, Prof. Kazuki Kurihara● Simulation of submillimeter electromagnetic wave propagation● Development and application of far-infrared molecular lasers

Cooperative research group 3.

Materials evaluation in the far-infrared region● Mechanical characterization of high-quality ceramics

Prof. Yoshiro Iwai, Associate Prof. Tomomi Honda● Surface characterization of new materials formed using high-power far-infrared technology

Research support organization● Research advisers:● Coordinators:

Prof. Fumitaka Horii, Prof. Takao Mizusaki, Prof. Kiyomi Sakai

Dr. Tasaburo Saji, Dr. La Agusu● Research support staff:

Mr. Shigenobu Arakawa● Cryogen supply section:

Prof. Isamu Ogawa (section head)● Technical staff: Mr. Tomohiro Kanemaki, Mr. Takanobu Yamada, Dr. Takashi Furuya● Secretaries: Ms. Miyuki Morito, Ms. Yoriko Kuwashima,

Division of Research Promotion, Department for Strategic Planning & Promotion

4Advanced Gyrotron Project1 Advanced Gyrotron ProjectIn the FIR UF, on the basis of the achievements of the gyrotron study, a project for the development ofadvanced gyrotrons has been promoted for application in various studies. Representative results are shownhere.

1. Gyrotron with an internal converter, Gyrotron FU CW G Series
We commenced the development of CW gyrotrons equipped with a converter to produce a Gaussian beam.
We can apply these devices in a wide variety of scientific research areas.

Gyrotron FU CW GI

The first gyrotron of this series, which was used for the
direct measurement of positronium hyperfine splitting

Gyrotron FU CW GIII

Second-harmonic, high-power gyrotron for use as a
power source for pulsed ESR●Fundamental harmonics●Second harmonics●Power: 0.5 kW●Power: 0.4 kW●Frequency: 203 GHz●Frequency: 395 GHz

A second-harmonic

oscillation efficiency of
4% was realized using

a specially designed
electron gun.

Infrared image of thetemperatureContinuous operation

increasefor over ten hours wascaused by the radiation
Gyrotron FU CW GI

beam from the Gyrotron
FU CW GI.

achieved.
Gyrotron FU CW GIII

2. Compact gyrotrons - Gyrotron FU CW C Series
Using innovative designs for making gyrotron tubes compact, along with a compact magnet and rack-mounted

power supplies, we realized compact gyrotron systems. Each system can be installed within a 3-m2 floor space
and a height of 1.5 m.

Gyrotron FU CW CI

Gyrotron FU CW CII
CWCII

Compact SC
magnet●Frequency tunability●Fundamental harmonics: 107–205 GHz,

150–320 W●Second harmonics: 290–396 GHz,5

10–30 W
●Applications: Studies on magnetic
resonance and DNP-NMR●Frequency fixed●Fundamental harmonics: 203 GHz, 0.8 kW●With mode conversion system(Gaussian mode output)●Applications: Measurement of

positronium; operation withrack-mounted power supplies

Operation withrack-mounted
power supplies
Operation parameters●Cathode voltage: 20 kV●Beam current: 300 mA

Advanced Gyrotron Project

3. Development of a high-power pulse gyrotron
Using a gyrotron, the ion temperature of a fusion plasma can bemeasured up to 100 million degrees. For this application, more than 100

kW is required. Following the achievement of the world’s highest
second-harmonic oscillation, we now aim to realize even higher powers
with the fundamental harmonic oscillation.

Target power of a high-power gyrotron

Gyrotron

The optimum frequency is 300~400 GHz.

A high power exceeding 300 kW is required.
Fusion Plasma

A high-power pulse gyrotron

mounted on a 12-T SC magnet

Scattered wave
shows ion
temperature.

is under development for use on

LHD in the National Institute for
Fusion Science.

4. Stabilization of power

5. Continuous frequency tunability

The stabilization of the output power over a

The continuous frequency tunabil-

cation of the gyrotrons. A highly stablecationlong time interval is necessary for the appli-

ity is very important for the appli-

oscillation within a power fluctuation of 0.6%

of

the

gyrotrons.

We

realized a 400-GHz-band gyrotron

was realized by PID feedback control.

with a frequency tunability greaterthan 4 GHz using the mechanismof backward wave oscillation.

6. Development of high-performance electron guns
For the advancement of the gyrotrons, high-performance electron guns are needed to emit electrons as a
generator of electromagnetic waves. We developed high-performance electron guns using an original design
methodology.

CathodeCathode (Filament on)

Electrons emitted from the cathode wind around the magnetic field lines.

6Material processing

2 Materials science in the high-power far-infrared region
The applied research on the gyrotron is one of the most important research fields at the FIR UF. There, for the
first time in the world, ESR measurements were successfully performed using a gyrotron. This new technology
has been applied in solid-state physics as well as studies of advanced gyrotrons. Studies of gyrotron applica-

tions have led to applied research in the various aforementioned fields. We also developed an original materi-als processing system with the world's highest frequency (300 GHz) and advanced the study of materials
processing with high-frequency electromagnetic waves. We continue to improve these new technologies of thehigh-power far-infrared region.

1. Material processing with gyrotrons
Heating by an electromagnetic wave at 2.45 GHz is the technique generally employed by microwave ovens. At

the FIR UF, experiments on the heating of materials can be performed with electromagnetic waves at frequencies 100 times that of the microwave oven, owing to the high-frequency and high-power capabilities ofgyrotrons. On heating by an electromagnetic wave, the energy is provided directly to the molecules, yielding amaterial unlike that produced by conventional heating. Thus, the characteristics of materials can be improved,with added functions, by tuning the frequency and output power of the electromagnetic waves.

The world's first 300 GHz/2.3 kW high-power electromagnetic wave irradiation system

28 GHz/15 kW high-power electromagnetic wave irradiation
systemFeatures of material processing by electromagnetic waves●Ceramics (materials for sintering) themselves are heated.
●We

can realize a reaction process without a thermal

equilibrium, using materials with different electromagnetic-wave absorption characteristics (differential heating).

●Innovative

material development using special effects(“non-thermal effect,” electromagnetic wave effects).

The frequency dependence of the apparent activation energy of the high-purity alumina ceramics
was revealed by 28- and 300-GHz electromagnetic-wave sintering experiments.

7

Condensed matter physics

2. Development and application of the high-frequency magnetic resonance technique
It is interesting to study the magnetic properties of a material under the extreme conditions of high magnetic
fields and very low temperatures because the basic and fundamental physics in condensed matters are often

revealed. We can investigate these properties on the microscopic scale, inside the material, using the magnetic resonance technique over a wide frequency range.
mm-wave vector network
analyzer (MVNA)

FFT-NMR spectrometer

Magnetic field: 18-T static field, 40-T pulsed field
Temperature: 300~1.5 K (liquid He)~0.1 K (3He/4He dilution refrigerator)
Frequency:
Electron spin resonance (ESR): up to 800 GHz (MVNA)
Nuclear magnetic resonance (NMR): 5–400 MHz (300-W pulsed RF)

Example of ESR/NMR double resonance

Evidence of dynamic nuclear polarizationof 31P lightly doped in silicon and control of
nuclear polarization by applying RF pulses(Y. Fujii et al., Proc. of FIRT 2012)

3. Development of high-frequency electron spin echo measurement system
The electron exhibits both electric and magnetic properties. The magnetic properties have mainly been used inmagnets. With the development of quantum mechanics, the realization of spin electronics and quantum
computers using a quantum magnetic property (spin) of the electron is attracting considerable attention.

By measuring with irradiation pulses of a few nanoseconds (approximately a billionth of a second) with a highfrequency and high-power electromagnetic waves from a gyrotron, we can examine the dynamic characteristics of the electron spin and control it to realize these new quantum applications.

High-frequency electron-spin
system under developmentechomeasurement

Ultra-short pulsed 154 GHz gyrotron output, 10- and20-ns, while maintaining the coherency using alight-driven semiconductor switching device8THz-TDS

3 Spectroscopic and application research using THz waves
The Terahertz Science Research Group has conducted
THz spectroscopic studies in materials science and has

developed THz techniques for non-destructive inspection.
Our major topics are as follows:●Development and application of novel THz-wave emitters anddetectors●THz optical and spectroscopic research using broadband THz

waves●Time-domain coherent anti-Stokes Raman scattering (CARS)

spectroscopy in the THz region

Terahertz time-domain spectrometer

In THz time-domain spectroscopy (THz-TDS), we measure the temporal shape of broadband THz waves withfemtosecond time resolution. By transforming the time-domain data to the frequency domain, we obtain THz

spectra in the range of 0.1–5 THz (frequency-domain data). We use femtosecond-pulse lasers andphotoconductive switch devices to generate and detect the THz waves.

0.17 ps108

Temporal shape of terahertz wave

>105

Power spectrum of THz wave

1. Development and application of novel THz-wave emitters and detectors:
detection of THz waves by electro-optic sampling with Cherenkov phase-matching
As a novel THz wave detection method, an electro-optic(EO)

sampling

method

based

on

a

Cherenkov

phase-matching scheme was developed. This method

allows any optical sampling wavelength to be used, by
adjusting the phase-matching angle between the THz
wave and the sampling beams.

We also developed a heterodyne

EO sampling method, whereby
the intensity modulation of thesamplingbeam

isdetected

without using any polarization
optics.

Sampling
pulse

LiNbO3 crystal

9

THz waveforms detected by EO sampling with
Si-prism-coupled LiNbO3 crystal in the
Cherenkov-phase-matched heterodyne scheme.

THz-TDS
2. THz optical and spectroscopic research using broadband THz wave:
superfocusing of THz wave
It is difficult to focus a freely propagating THz wave into a beam with a submillimeter diameter, owing to thediffraction limit. Focusing a THz wave into a diameter less than 100 μm can be achieved using a metal

waveguide comprising two tapered-metal plates. By this “THz superfocusing effect,” THz waves are available
for a wide range of applications, e.g., the inspection of a small amount or a very thin sheet of samples. We

signalhave been performing fundamental research on THz superfocusing, as well as studies of its applications.

reference THz wave
transmitted THz wave

Delay time (ps)Blue and red lines represent transmitted THz
waves through air and through a tapered-metal
waveguide, respectively.

Dispersion curves of THz wave propagation
through a metal-parallel-plate waveguide

3. Time-domain coherent anti-Stokes Raman scattering spectroscopy in the THz region
To study the molecular vibrations in the THz frequency region, we are developing coherent anti-Stokes Raman

scattering spectroscopy (THz-CARS), in which the CARS signal is detected in the time domain. In this novel

CARS spectroscopy, low-frequency Raman spectra, e.g., at several tens of GHz, can be measured using
chirp-controlled optical pulses from a single femtosecond laser as the pump. This eliminates the need for two

frequency-stabilized lasers with a THz difference frequency, as is required in conventional CARS spectroscopy.

Schematic illustration of the THz-CARS spectroscopy

10International research collaboration
International research collaborations● The FIR UF has concluded agreements for academic exchange and MOUs with 11 and 11 overseas institutes,

respectively, for the development of international joint research projects.

● FIR UF is the center of the international consortium “Promoting International Collaboration for Development andApplication of Submillimeter Wave Gyrotrons,” with 6 overseas and 2 domestic institutes.

● Foreign visiting professors are invited under the bylaws of the FIR UF, and one or two of these professors arealways present at the FIR UF to contribute to the promotion of the international joint research projects.

Institute for Plasma Research,
Stuttgart University(IPR-SU),
Germany●Development ofsubmillimeter-wave
gyrotrons●Applications in plasma
diagnostics

Science-Technical Center ofMicrotechnologies, D. Y.
Efremov Institute ofElectrophysical Apparatus(NIIEFA), Russia●Generation andapplications of strong
particle beams andelectromagnetic waves

Institute of Applied Physics ,Russian Academy of
Science(IAP-RAS), Russia●Development andapplications ofhigh-frequency gyro-devices

Institute for High Power
Pulse and Microwave
Technology, Karlsruhe
Institute of Technology(IHM-KIT), Germany●Development andapplications ofhigh-quality gyrotrons●Development ofhigh-efficiency
transmission lines for
submillimeter-wave
gyrotronsof electron guns forcompact shower devices
and submillimeter-wave
gyrotrons

devices withsemiconductors

Faculty of Science,
De La Salle University,
Philippines●THz radiation fromsemiconductors withnanostructure

Faculty of Mathematics
and Natural Sciences,
University of Haluoleo,
Indonesia

Institute for Solid State
Physics, University ofLatvia, Latvia●Physics of gyrotrons in THz

range

Guest Professor G. N. C. Santos from De La Salle
University, Philippines

11

gyro-devices in the THz
range and applications inbioscience●Development of THz●DNP-NMR spectroscopy●Analysis and optimization●Development of

National Institute ofPhysics, University of thePhilippines, Philippines

NMR Center, University of
Warwick, UK

Institute of Electronics,
Bulgarian Academy of
Sciences(IE-BAS), Bulgaria

Center for THz-Bio
Application Systems, Seoul
National University,
Republic of Korea

Usikov Institute for Radio
Physics and Electronics,
National Academy of
Science of Ukraine(IRE-NASU), Ukraine●Applications in material

processing●Development andapplications of radiation
sources in millimeter toTHz-wave range

Members of collaboration with Usikov Institute for Radiophysics
and Electronics, NASU, Ukraine

Topics of collaborative research works
Collaborative research works
By collaborating with various institutions, the FIR UF achieved innovative research and development in a widearray of fields, including fundamental science, bio-science, and materials science.

1. Analysis of the structure of protein molecules by DNP-NMR spectroscopy(Collaborations with Institute for Protein Research, Osaka University, and NMR Center, University of Warwick (UK))● The high magnetic polarization of the electrons is transferred to the nuclei by the irradiation of the sample

with high-power THz radiation from the gyrotron (Dynamic Nuclear Polarization; DNP), and as a result, thesensitivity of the NMR spectroscopy is highly enhanced (DNP-NMR). This method will be applied for the
analysis of protein molecules and the structure of the polymer surface.

● At Osaka University, an enhancement factor of 46 was achieved using a 395-GHz band gyrotron.

● At the University of Warwick, the NMR sensitivity was enhanced by 60 times using the DNP-NMR methodwith a gyrotron.

Principle of DNP-NMR spectroscopy

Irradiation of high-power THz radiation causes resonanttransitions, indicated by the red and blue arrows.

DNP-enhanced NMR spectrum measured
at Osaka University(left: conventional NMR, right: DNP-NMR)

2. Direct measurement of the hyperfine structure of positronium: a subject inelementary particle physics(Collaboration with the International Center for Elementary Particle Physics, The University of Tokyo)● The high-power THz radiation from gyrotrons is also applicable in elementary particle physics.

● By irradiating with the high-power THz light and measuring the γ ray emission simultaneously, the first direct measure-ment of the difference between the energy levels of the ortho- (o-Ps) and para-positronium (p-Ps) was achieved.

A schematic drawing of transition between
energy levels and emission of γ ray

Frequency dependence of transition rate between
the energy levels of o-Ps and p-Ps.
Drawing of measurement devices

The transition rate is enhanced at a particular frequency
corresponding to the difference between the energy levels.

12

Topics of collaborative research works
3. Study of Semiconductor Nanostructures with THz Waves– THz emission from Semiconductor Nanostructures –(Joint Research with National Institute of Physics, University of Philippines)● When semiconductor nano-structures, such as nanowires, are irradiated by femtosecond laser pulses, THz

waves are emitted depending on the structure. The precise THz emission mechanism remains unknown; none-

theless, such THz emission can be utilized to examine nanostructures. In addition, it is possible to realize
efficient THz emission devices based on the semiconductor nanostructures.

Microscopic image of GaAs-AlGaAs core-shell
nanowires deposited on Si (100) substrates taken witha scanning electron microscopeTHz time-domain signals (left) and THz power spectra (right)
from the GaAs-AlGaAs CSNWs ((a) and (b)) and the SI-GaAs
substrate ((c) and (d)) without a magnetic field (no B), with a
Bup polarity, and with a Bdown polarity.
※The figures excerpted from Appl. Phys. Lett. 102 (2013) 063101

4. Study of the possibility of a Bloch oscillator by high-power THz irradiation
with high power THz radiation(Collaboration with Institute of Industrial Science, The University of Tokyo)● A Bloch oscillator using a semiconductor superlattice is used to realize a frequency-tunable solid-state THz radia-

tion source covering a wide frequency range.

Coupled system of an antenna and a superlattice fabricated at Institute of Industrial Science, The University of
Tokyo

13

By high-power irradiation with a frequency of 0.395 THz,
the V-I characteristics are changed. Thus, the high-fielddomain disappears, allowing a Bloch oscillator.

Topics

TopicsFIR UF organized the 5th International Workshop on Far-Infrared Technologies 2014
The 5th International Workshop on Far-Infrared Technologies 2014 (IW-FIRT 2014), March 5–7, 2014, was organized
by FIR UF and co-sponsored by six academic societies. This workshop comprised 24 invited talks (eleven speakers
from abroad, seven speakers from domestic institutions, and six

FIR UF researchers) and 5 contributed talks, together with 19

poster presentations. A total of 84 researchers (14 from abroad)participated in the workshop. This workshop put emphasis on

the development of advanced THz gyrotrons, new disciplines
and possibilities of condensed matter physics with far-infrared

light, and new THz spectroscopy with gyrotrons. Many interesting reports were presented and stimulated discussion was

carried out. We hope many new works will appear in near future.

FIR UF hosted International Symposium on Developmentof Terahertz Gyrotrons and Applications

The International Symposium on Development of

Terahertz Gyrotrons and Applications was held at the

FIR UF from March 14–15, 2013. This symposium
was combined with a congress of the international
consortium (p.11). There were six participants fromoverseas

institutions,thirteen

fromdomestic

institutions, and ten from the FIR UF. In the summary
session, the evolution of the research due to thedevelopment of the THz gyrotrons and their applications in various fields, as well as the future prospectsof the THz gyrotron, were discussed. It was adopted as a summary of the symposium that the importance of theframework for international collaboration, with the FIR UF as the core institution, was confirmed and that further
development of the capabilities of FIR UF as the worldwide research base is required.

Collaboration for research on high magnetic field - KOFUC network
The “High Magnetic Field Collaboratory Plan” is a theme of the Ministry of Education, Culture,
Sports, Science, and Technology (MEXT)’s large research projects. The plan is to build adomestic research base with high-magnetic-field facilities and enhance these facilities. In order

to construct this base in western Japan, three research centers (FIR UF; Center for Advanced

High Magnetic Field Science, Osaka University; and Molecular Photoscience Research Center,
Kobe University) agreed to cooperate. This collaboration is called the “KOFUC network.”

New helium liquefier and helium gas
recovery system
The cryogen supply section of the FIR UF has performed the management
and operation of the Cryogenic Laboratory. The Cryogenic Laboratory

supplies cryogen (liquid nitrogen, liquid helium) in University of Fukui. The
first helium liquefier was installed in our university in 1968. Cryogen has

been foundational to the study of high-frequency gyrotrons. A heliumliquefier and gas recovery system were renovated in 2013. The liquefaction ability was improved (to 60 L/h in pure helium gas operation), and thestorage capacity was increased.

14

FIR Center map

Major equipment of FIR UF
Gyrotron with an internal converter
Gyrotron FU CW G I

1 THz gyrotron FU CW III
with a 20-T superconducting magnet

Far-infrared molecular laser

Cryogenic Laboratory
3F

6F

WC
EV

WC
EV

3F
609

EV
C301

608

C302
301

2F

601

EV

C303

602 603 604 605 606 607

EV

2F

5F

WC

WC
EV

203

WC

C304

505

C202

504

C201

C203

503
201

501

202

502

1F
1F

WC
102

EV

101
101

4F

WC
EV

EV

C101
406

C103
401

lobby

28-GHz microwave sinteringsystem（Room 101）

Gyrotron FU CW IIA
Gyrotron FU CW IIB●Gyrotron FU CW III (Room 301)
Gyrotron FU CW IV●Gyrotron FU CW G I (Room 301)
Gyrotron FU CW G III
Gyrotron FU CW G V
Gyrotron FU CW C I
Gyrotron FU CW C II
Pulse gyrotron
Pulsed THz gyrotron
15-T helium-free superconducting magnet●Far-infrared molecular laser (Room 203)
Backward-wave oscillator system
Millimeter-wave orotron

15

402 403

C104

405
C102

404

THz time-domain spectrometer（Room 405）

THz ESR spectrometer（Room C104）●28-GHz microwave sintering system (Room 101)24-GHz microwave sintering system●THz time-domain spectrometer (THz-TDS) (Room 405)

Regenerative amplifier system of femtosecond pulse laser
Atomic force microscope (AFM)
Cavity dumping system (10-fs pulse)
Optical parametric amplifier system of femtosecond pulse laser
Self-mode locking system (100-fs pulse)●THz ESR spectrometer (consisting of 18T-SCM and MVNA) (Room C104)
18-T superconducting magnet with variable temperature insert or3
He/4He dilution refrigerator (18T-SCM)
Millimeter-wave vector network analyzer (MVNA)
Electromagnetic-wave anechoic room
Submillimeter-wave plasma-scattering system● indicates an apparatus shown in the pictures

Research activities and publications

Research activities and publications

Research activities
2009

2010

2011

2012

2013

Total

Original papers

12

21

10

25

17

85

Reviews and reports

6

18

9

0

2

35

78（24）

43（8）106（31）53（8）61（17）

341（88）

68（1）

96（9）

86（9）

91（3）

84（2）

425（24）

Books (including textbooks, translations)

0

1

4

2

1

8

FIR Center Report

8

4

9

5

2

28

Agreements for academic exchanges

8

9

10

11

11

49

MOUs for international collaborations

9

9

9

10

11

48

Cooperative scientific research projects underbilateral agreements

3

3

3

3

2

14

International collaborations

25

23

19

22

21

110

Domestic collaborations

18

17

25

27

40

127

Visits to overseas institutes and/or conferences

26

22

32

20

20

120

Visitors from overseas

26

5

15

8

17

71

Domestic visiting professors

4

5

5

4

4

22

International visiting professors

3

4

4

4

6

21

Postdoctoral fellows

4

5

5

4

5

23

FIR Center seminars

19

16

9

11

15

70

Presentations at international conferences(invited presentations)
Presentations at domestic conferences(invited presentations)

Research publications
In addition to our publications in academic journals and at conferences, our recent research results andachievements are published in our “Annual Report” and in “Research and Development in the Far Infrared Region”(in Japanese), which are released annually by the FIR UF. We also organize the International Workshop on

Far-Infrared Technologies (IW-FIRT) every few years and publish its proceedings to summarize the recent
achievements of the FIR UF and those of the international joint projects. For the fast publication of our latest

research results, preprints of our papers are issued as the “FIR Center Report” and are posted on the FIR UF
webpage.

FIR Center seminar
The FIR UF holds open seminars on the FIR and THz region by active researchers invited from across the world.
We have 10–20 seminars per year. The schedule and other information can be found at the FIR UF webpage.

16

How to join FIR UF
How to participate in FIR UF research
There are programs for international students to study at the University of Fukui:
A. Global Engineering Program for International Student (GEPIS)

B. Global Network Engineering Program for International Students (GNEPIS)
C. The University of Fukui Student Exchange Program (UFSEP),

D. The University of Fukui Exchange Student Program (UFESP).

GEPIS and GNEPIS are programs for regular students, and UFSEP and UFESP are for exchange students.

http://ryugaku.isc.u-fukui.ac.jp/english/manabi/fukudai_program.html
Undergraduate or graduate students at the
University of Fukui can participate in studies at the

FIR UF. Admission information can be obtained at
the following website:

http://www.u-fukui.ac.jp/eng/index.html
At the FIR UF, a number of PhD fellows areengaged in our research. If you are interested in

the PhD positions at the FIR UF, please contact
the Center members listed on pp. 3–4.

Messages from foreign students
Having spent time studying in Japan, especially in FIR-Center of University of Fukui, I got lots ofmemories not only in academic matters but also in all aspects of my life. During my first days in Japan, I
did experience confusion on both language and research. Fortunately, students in the Center werealways there to provide kind help. Studying and doing research at the FIR UF blessed me with theopportunity to join the world-class research and development center with ahigh-power far-infrared source like the gyrotron and its applications, as well as

THz science. Moreover, I also had the opportunity to meet and discuss various
fields with experts from various countries visiting the Center. The emotional bondwill sustain forever, and memories of Fukui will always be here with me. I do hopeto still have updated news from the University of Fukui and I am looking for every
chance to visit the place again.

( I Nyoman Sudiana, former doctoral student of University of Fukui, Indonesia)

Dr. Sudiana (left)

I am happy with my decision to come to Japan to pursue a PhD in Applied Physics while doing researchon THz science at the FIR UF. I can really say that I came to the right place and I joined the right
institution. the FIR UF is a great research environment not only for the Japanese, but also for foreign

nationals. I arrived in Japan not knowing how to speak, read, or write Japanese, but this did not set meback. I was able to embrace my new life here with relative ease because the people at the FIR UF arevery supportive and easy to get along with. In addition to having opportunities to participate inworld-class research activities, being part of the FIR UF allows me to make themost out of my stay in Japan. I am never bored as there is always something to

do. Outside the FIR UF, there are also opportunities to make more friends, visit
other places, and experience the sights, culture, and local life, especially throughthe various programs of the University of Fukui’s International Center and Fukui’s
International Association.
Ms. Mag-usara

17(Valynn Katrine P. Mag-usara, doctoral student of University of Fukui, from
Philippines)

Messages from students and postdoctoral fellows
About living in Fukui - Message from postdoctoral fellows from overseas
We joined the FIR UF in the end of 2012 as postdoctoral fellows working in the THz science group of
Prof. Tani. The FIR UF offers comprehensive resources and well-equipped laboratories enabling
cutting-edge research. Quarterly change of guest professors and many visitorsfrom Japan and overseas expand the inspiring and motivating environment of the

FIR UF. Right from the beginning, all FIR members supported us in every aspect,scientifically as well as in everyday life. Here, Fukui provides various options,
ranging from traditional Japanese experiences (e.g., in the Eiheiji Temple) to thebeautiful countryside. Fukui is only a stone’s throw from the ocean as well as
mountain areas, and after short train rides, one reaches Japanese metropolises like

Nagoya or Osaka. In Fukui, every visitor can taste great food, for example, freshsushi, Echizen crab, and local soba noodles.

(Dr. Gudrun Niehues and Dr. Stefan Funkner)

About University of Fukui

URL: www.u-fukui.ac.jp

Population statistics of University of Fukui

The University of Fukui comprises three faculties: the Faculty of Engineering, Faculty of Education andRegional Studies, and Faculty of Medical Sciences. More than 5,000 students, including over 150
foreign students, study at these faculties. The Faculty of Engineering is supported by around 180
professors and associate professors, including those of the FIR UF.

Bunkyo Campus Map
16
15

1

8 14

1

13 5

2

11

FIR UF

19

1
25

21

17

3
9

7

4

18

20

6
10
22

3
24

12

3

23

1 Faculty of Education and Regional Studies

2 Integrated Research Center for Educational

Practice
3 Faculty of Engineering
4 Cryogenics Laboratory
5 Center for Interdisciplinary Studies
6 University Library
7 Headquarters for Innovative Society-Academia
Cooperation
8 Admission Center

143

9 FIR UF

19 Extracurricular Activities Center

11 Center for Computing and Network Services

21 Shop and cafeteria

10 Health Service Center

12 Central Administration Building
13 Student Services Center

14 International Student Center

15 Tennis courts and volleyball courts
16 Athletics ground

20 University Hall
22 Guest house
23 Main gate

24 Academy Hall

25 Integrated Research Building

17 Gymnasium

18 Swimming pool18

Campus Location, University of Fukui
FIR UF is located on Bunkyo Campus
uryu

Rive

r

To Mikuni

Kuz

Fukui-kita I.C

a
za
w
na
Ka
To
Nishibetsuin

Echizen Railway

JR Hokuriku Line

Tawara-machi

Route 416

To Katsuyama/
Eiheiji Temple

To Katsuyama/
Eiheiji Temple

Hokuriku Expressway

Highway Sabae-Maruoka line

Fukudai mae Nishifukui

To K
anaz
awa

To Kanazawa

Awara Highway

Meiji-bashi
BridgeTo Kanazawa

To Awara

To Mikuni

Hino River

Nittazuka

Bunkyo campus

Fukui-guchi

Route
8

Shin-fukui
Tsukumo-bashi
BridgeRoute 158

To Onoruga

railway

To Ts
u

Asuwa River
To Maibara

Fukui Tetsudo

To Takefu

Mt. Asuwa
Park

Fukui I.C

Fukui

Saiwaibashi
BridgeMatsuoka
campusTo Katsuyama/
Eiheiji Temple

uga

To Tsur

Getting to FIR UF

By taxi: A taxi service is available at the JR Fukui station, taking you to the Bunkyo Campus in ~10 min.
By train: Take the Mikuni-Awara line, on the Echizen Railway, adjacent to the JR Fukui station at the Fukui station.
Alight at Fukudaimae-Nishi station. The journey takes ~10 min.

From Tokyo
By trainTake the JR Tokaido Shinkansen Line from Tokyo to
Maibara (approximately 2 h and 40 min). There, change
trains and take a limited express train on the JR Hokuriku
Line to Fukui (~1 h).

By carNiigata
The Sea of Japan

Kanazawa

Fukui

From Osaka
By train
By carTake the JR limited express train, Thunderbird, at the
Osaka Station, which takes you directly to the Fukui
station in ~2 h.
Take the Meishin Expressway from Osaka to the Maibara
Junction. Enter the Hokuriku Expressway and continue toFukui I. C. (~ 3 h total).

ToyamaKomatsu Airport

By careway

xpressriku E

Hoku

MaibaraChuo Expressway

Kyoto
Osaka

Meishin
Expressway

NagoyaFrom Nagoya
By trainNaoetsu

ku Lin

okuri

JR H

Take the JR limited express train, Sirasagi, at Nagoya
Station, which takes you directly to the Fukui station via
Maibara in ~2 h.

Tomei Expressway

The Pacific Ocean

Take the Meishin Expressway from Nagoya to the
Maibara Junction. At the Maibara Junction, enter the
Hokuriku Expressway and continue to Fukui I. C. (~2 hand 30 min).

Bunkyo 3-9-1, Fukui 910-8507, Japan
TEL：＋81-776-27-8680 FAX：＋81-776-27-8770
URL

http://fir.u-fukui.ac.jp/

Printed in November 2014

Echigoyuzawa
Kanetsu Expressway

Take the Tomei Expressway from Tokyo and continue
through Nagoya on the Meishin Expressway until you reachthe Maibara Junction. Enter the Hokuriku Expressway andcontinue to Fukui I.C. (~ 7 h).

ine

Fly from Haneda Airport to Komatsu Airport (journey of ~1h). At Komatsu Airport, take a shuttle bus to Fukui.

JR
Sh Jo
ink etsan u
senL

By airTokyo
Haneda Airport
JR Tokaido
Shinkansen Line