Nonlinear Photonics Group
Hattori-Kano-You Group
Graduate school:
Subprogram in Applied Physics, Program in Engineering Sciences,
Program in Humanics (Kano)
Undergraduate course:
Applied Physics, College of Engineering Sciences,
Bachelor’s Program in Interdisciplinary Engineering (Hattori)

http://www.bk.tsukuba.ac.jp/~thz/What is “Nonlinear Photonics”
 Optical phenomena induced by intense laser

light, such as new-wavelength-light generation
or creation of novel states of matters, are called“Nonlinear optical phenomena.” We use
nonlinear optics for various application.

Research subjects
 Terahertz spectroscopy of biological tissues and materials

for the understanding of water molecule dynamics
 Sensing using terahertz waveguides
 Development of new measurement techniques using
terahertz waves
 Development of new pathological diagnosis

using nonlinear Raman imaging
 Visualization of the reprograming process of iPS cells
 Study of lipid metabolism in brown adipocytes

Current status of the group
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Professor
Toshiaki Hattori （服部 利明）
hattori@bk.tsukuba.ac.jp, 3F625
Assistant Professor Borwen You （游 博文）
you.borwen.gt@u.tsukuba.ac.jp, 3F530
Associate Professor Hideaki Kano （加納 英明）
hkano@bk.tsukuba.ac.jp, 3F607
Students
Master course
12PhD course
1
Undergraduate (4th year) 6
Research students
5（as of October 2019）
Labs
3G217, 3G411, Natural Science Building D205
Student rooms
3G216, 3M408
After graduation
Hamamatsu Photonics,Tokyo Electron, Ricoh, Panasonic, NTT West, Terumo, SIIX, Aisin AW, Shimadzu,
Japanese Bankers Association, Kao, Toshiba Medical, JR East, NHK, Furukawa Electric, Casio, SankiEngineering, Asahi Glass, Tokyo Electric Power, Toyota Central R&D Labs, Shibaura Mechatronics,
Sumitomo Heavy Industries, Japan Electrical Safety & Environment Technology Laboratories, Ruhr-Univ.
Bochum, Mitutoyo, Hokkaido Electric Power, Southampton Univ., Fuji Technical Research, Fujitsu, IREP,Sharp,V Technology, Asahi Kasei, Wanbishi Archives, Canon, Toshiba, JR East, Fuji Heavy Industries,
Sumitomo Life Insurance, Sumitomo Chemical

Nonlinear optical phenomena
 Sum frequency & difference frequency

generation

ω1 , ω2 ⇒ ω3 = ω1 + ω2
ω1 , ω2 ⇒ ω4 = ω1 − ω2Terahertz wavegenaration

 Optical wave mixing
ω1 , ω2 , ω3 ⇒ ω4 = ω1 − ω2 + ω3
 Multi-photon absorption& emissionωω

Coherent Ramanscattering

What is “Terahertz Waves.”“Radio Waves”

Terahertz GapElectronics
Low Freq., Radio, TV, Microwave, mm wave

IR / vis / UV

x-ray

γ-ray

“Light”
Electromagnetic frontier between radio waves and light. Photonics
Radio wave
Long wavelength
Low photon energy
Large diffraction

Terahertz waves
0.03 - 12 THz

Light
Short wavelength
High photon energy
Propagates straightly

Applications of terahertz waves
 Imaging
Security inspection, product inspection, medical diagnosis
Drugs, explosives and combustibles,semiconductors・・・・
Transmits through cloth, paper, etc.
Absorbed by water. / Reflected by metals.
Bio-safe. Spectroscopy for material identification.

 Spectroscopy
Bio-materials, semiconductors, space,environment・・・・

 High-speed communication

THz spectroscopy apparatus
From optical chopper

Lock-in amp.

Balancedetector

WP

Pellicle
Sample space

To delay stage

PM3PM6ZnTe

PM4PC

λ/4

Wire gridAperture
SiPM5OWInAs

PM1PM2
To lock-in amp.
Optical chopper

N2 purge box

GTPOWM

Pump pulse ↑← Probe pulseBSTo PCMM

Delay stage

Ti:Sapphire laser
10.5 fs 780 nm 500 mW

Terahertz imaging
High-speed THz video

Metal strips

Terahertz imaget = 0 ms

2 ms

4 ms

6 ms

8 ms

10 ms

12ms

14 ms

16 ms

18 ms

20 ms

22 ms

Skin observed using terahertz waves
stratum corneum（0.02 mm）
epidermis（0.1～0.3 mm）
Composed ofcollagen, elastin, etc.

dermis（2～3 mm）
subcutaneous tissue

Dermis can affect skin resilience.
How is the relationship of aging with the water characteristi
65Im [ε]4Dielectric spectra ofdermis with different
water contents

384%
62%
41%
20%
11%
PBS

2
10
0.5

1.0

1.5

Frequency (THz)

2.0

Gels observed using terahertz waves
・Agarose: polysaccharide, principal component of agar

・3-D polymer network contains water in agarosehydrogel.
Agarose gel

polymer
Sol-gel transition of agarose

solvent
coolingcoolingheating heating

Hydration of various molecules Solutes are stabilized by interaction (such as
electrostatic, hydrogen bond, etc) with solvents. This iscalled solvation. (Hydration in aqueous solutions.) Water molecules around the solute can have specialproperties.
 Functions of bio-molecules are enabled under thiscircumstance.
 Terahertz spectroscopy can show us
the dynamical properties of hydration
layer A water.
proteinlayer B

 Hydration ofpolymers

Advanced THz Optics-1

Research purpose-1: System on the chips
Knowledge
background:1) Integrated Optics
2) Integrated Sensors

Advanced THz Optics-II
Research purpose-I1: Artificial materials

Knowledge background:1) Optical thin-film
engineer2) Optical properties ofmaterials3) Photonic/plasmonicstructures

Advanced THz Optics-III

Research purpose-III: Fiber sensing technology
Knowledge background:
1) Fiber Optics
2) Ultrafast Optics
3) Time-Domain
SpectroscopyExploring new horizons oflife and medical sciencesusing nonlinear Raman
spectroscopy

Spectra are letters from molecules
Raman spectraω1ω1ωRamanωRamanIntensity (arb. units)

http://www.stemcellsinc.com/
Science/Stem-Cells-101.htm

Whole cell
proteins
RNAs
DNAslipids

1800

1600

1400

1200

1000

Raman shift / cm-1
I. Notingher, Sensors 7, 1343 (2007).

800

Nonlinear Raman by white-light laser
Development of whitelight laser source(JSPS bilateral with France)coherent anti-Stokes
Raman scattering(CARS)
ωCARS
ωCARS
ωCARS
ωCARS
ωCARS
ωCARS
ωCARS

2007~

proteinslipids

DNA/RNAmerged

http://www.stemcellsinc.com/
Science/Stem-Cells-101.htm

M. Okuno et al,
Angew. Chem. Int. Ed. 49, 6773 (2010);
PLoS ONE 9, e93401 (2014).

ω1 ω2

ω1

ωCARS

Research Highlight Unexpectedly found
4th SHG-active protein filament(2)One-photon fluorescence

Two-photon fluorescence & SHG(present study)DNA(fluorescence)

Rootletin(fluorescence) (SHG)
Ac-Tubulin(fluorescence)(1)(1) Wheway et. al. Landes Bioscience , 10, 1 (2014)(2) Rachel et. al. HMG, (2015)

Excitation laser : 775 nm
Exposure time : 500 ms/ pix
Image area : 25 μm2

Rootlet/Rootletin is
SHG active !

Nonlinear Raman @ Univ. of Tsukuba
iPS & brown adipocytes（Medical
dept., Prof. Hisatake lab.)

Eye tissues（Univ. hospital,ophthalmology, Prof. Ohshika
and Prof. Kaji)

Molecular
fingerprinting
by CARS
Algae（dept. of life &envirnment,Prof. Watanabe)
opticalTAG

CARS

H. Segawa et al., J. Biophotonics (2013)

Chirality
squalene

http://en.wikipedia.org/wiki/Chirality

K. Hiramatsu et al., Phys. Rev. Lett. 109, 083901 (2012).

For more details…

https://www.tsukuba.ac.jp/en/people-list/tsukuba-future-036