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Experiment
Polarization Terahertz Spectroscopy Application to Theophylline Anhydrous Single Crystal for Vibrational Mode Assignment
7
Purpose Summary A single crystal of theophylline anhydrite, large and thin enough
for wide range THz transmittance spectroscopy could be successfully fabricatedby Temperature Difference Method (TDM) in aqueous solution.
Wide range polarization spectroscopy at low temperature was shown to be useful to assign vibration modes with the aid of DFT calculation.
Sample preparation Results and discussion
0 10 20 30 40
Theophylline anhydrous
Inte
nsity
(a.u
.)
(deg)
grown crystal
XRD - 2 measurement
Pna21
P21/c
Theophylline monohydrate
P21/n
5.0 mm
1.0 Grown single crystal
Orthorhombic Pna21a=24.612,b=3.8302,c=8.5010
(110) reflection
0 1 2 3 4 5
0
1
2
3
parallel to
Frequency (THz)
Abs
orba
nce
Theophylline anhydrous single crystal70 K
1.060
0
30
60
90
1.797
2.0842.788
4.070
5.112
1.212 1.761 2.853 3.9134.390
single crystal
70 KSmoothing 50GHz
1 2 3 4 5
1
2
0Frequency (THz)
Abs
orba
nce
Theophylline
0.85
1.06
1.231.47
1.79
2.092.79
10 wt% PE pellet
2.87
3.96
powder
70 K
Pole Figure measurementto (110) reflection
Powder XRD measurement of crushed crystal
1/T
lnc
hydrate
anhydrous
0.0029
71
@1013 hPa
Temperature Difference
Crystal growth from aqueous solution
low temperature hydrous
high temperature anhydrous
Single crystal growth of Theophylline anhydrous for THz transmittance spectroscopy
8278
cooler
crystalcell
heat sinkpeltiercooler stirre
r
pump
saturated aqueous solution
82
78
heater
Air flow
air flow
CW GaP THz Spectrometer
Dryairpurged
Nb TES bolometer
MotorizedLinearStage
Chopper
LockinAmp
MotorizedRotaryStage
Collimater
DFB:Distributed FeedbacklaserECLD:modehopfree
ExternalCavityLaserDiodeYbFA:YbdopedFiberAmplifier
Collimater
Cryostat
YbFA
DFB
2channelFrequencyMeter
YbFA
ECLD
Powerfeedback
Powerfeedback
Frequencyfeedback
Frequencyfeedback
Nb TES: Nb SuperconductingTransitionEdgeSensor
CalculationDFT (Density Functional Theory) calculation with periodic boundary condition
Software package CRYSTAL09
B3LYP/6-31G(d,p) level
Fixed cell parameter
Y. Ebisuzaki, P. Boyle and J. Smith, Acta Cryst. (1997). C53, 777-779.
Geometry optimization start from crystal structure
defined by X-ray diffraction at room temperature
GaP
Frequency Absorption Direction(THz) (a.u.)
0.85
1.06 0.348
1.21 0.026
1.47
1.761 0.179
1.797
2.084 0.056
2.788 0.099
2.853 0.042
3.913 0.496
4.070 0.971
4.390
5.112 0.162
0 1 2 3 4 5
0
1
Frequency (THz)
Abso
rban
ce
102030405060
Inte
nsity
(km
/mol
)
B3LYP / 6-31G(d,p)Fixcell
DFT Calculation
Frequency Intensity Direction(THz) (km/mol)
0.696 0.80 0.737 0.99 0.796 1.18 1.212 4.74 1.235 3.65 1.344 1.80 1.723 2.84 1.726 0.14 1.955 19.64 2.160 0.04 2.190 0.14 2.663 2.50 3.477 0.10 3.562 1.34 3.616 0.68 3.993 18.13 4.049 20.46 4.170 58.02 4.419 4.83 4.604 3.23 4.777 1.02 4.793 5.71 4.958 3.04 5.058 5.55 5.063 10.55 5.462 17.39 5.466 9.37 5.469 0.59
Measurement
0.796 THz Theophyllineanhydrous
C7H8N4O2
drug for respiratory diseases
C7H8N4O2H2O
Theophylline monohydrate
DFT calculation
Polarization dependent spectra for anhydrous single crystalat low temperature
Direct comparison
Single crystal growth of Theophylline anhydrous Polarization THz spectroscopy of Theophylline anhydrous crystal
at low temperature Comparison absorption frequencies and intensities
between measurements and calculations
for THz vibrational mode assignment to obtain basic data to apply THz spectra
to pharmaceutical Product Quality Control
H2O
Supply a system (hardware and software)
Please find each vibration mode in PC (animation file)
Frequency range
Frequency accuracy &resolution
Power stability
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Improvement of CW GaP THz Spectrometer
Wide range and high resolution CW THz spectrometer combined with GaP THz signal generator and mechanically cooled bolometer
Motivation
CW GaP THz Spectrometer
Dry airpurged
Nb TES bolometer
MotorizedLinearStage
Chopper
Lock-inAmp.
MotorizedRotary Stage
Collimator
DFB : Distributed - Feedback laser
ECLD: mode-hop free External Cavity Laser Diode
YbFA: Yb doped Fiber Amplifier Cryostat
DFB
2 channelFrequency Meter
YbFAECLD
Powerfeedback
Powerfeedback
Frequency feedback
Nb TES: Nb SuperconductingTransition Edge Sensor
GaP
Next Step
Lens
Collimator
Frequency feedback
YbFA
THz wave
Nb TES bolometer
0 1 2 3 4 5 6
4K Silicon bolometer QMC Nb TES bolometer
Frequency (THz)
Out
put p
ower
(re
lativ
e va
lue)
T.Sasaki
Frequency range
Signal generator
Spectrometer
Frequency resolution
Feedback control of pump beams
at seed laser
Power stability
Feedback control of pump beams
at fiber amplifier
Easy operation, Maintenancefree
Parts for optical communication
Small size, Portable
Optical fiber coupling
1000
1
GaP crystal
THzwave3 = 1 - 2
2
IRlaserbeams
DifferenceFrequencyGeneration(DFG)
Ga
P
1.95 THz
GaPFiber Amp.Powerfeedback
Fiber Laser
Modehop-free ECDL
IR lens
25W
5W
0 2 4 610-4
10-3
10-2
10-1
1
10
Frequency (THz)
THz
outp
ut (a
.u.)
IR laser beam power: 5 W x 25W (not purged)
noise floor
> 4.5 orders
3W x 3W (purged by dry air)
~ 3 order
CW GaP THz Signal Generator
GaP
THz
DFB : Distributed FeedBack laser
ECLD: External CavityLaser Diode
FA : Fiber Amplifier
DFB
ECLD
FA
FA
Mirror
Polarizer
- Global helium shortage - Price rise
Using a cryostat with a tank storing liquid helium
- Refill Liq. He every 30 hours
Problem
2.7738 2.774 2.7742
3.4 Pa 70 600 1.8k
Frequency (THz)
THz
pow
er (a
.u.)
100MHz
2.773985 THz2.773977 THzNASA JPL
measurement
Summary
combining with a CW THz SG as a light source and a bolometer detector cooled by a mechanical cooler
1 2 3 4 5 6
1
2
0
Theophylline anhydrous plate (thickness ~ 100 m)
Frequency (THz)
Abs
orba
nce
300 K
70 K
An example ofTHz absorption measurement
Theophyllineanhydrous
Pharmaceutical drugfor respiratory diseases
System optical responsivity
System RMS output noise at 80 Hz
System optical NEP at 80 Hz
QMC instruments QNbB/PTC
THz power spectraof CW GaP THz SG
measured byQMC Nb TES bolometerand4 K silicon bolometer
168 kV/W
430 /
2.6 /
CW GaP THz Spectrometer
High accuracyHigh resolutionWide dynamic rangeHigh stability Long lifetime (durability)Easy maintenanceLow equipment costLow running cost
The spectrometer is now working as non-stop system
Next targetdevelop practical industrial applications
Applying high power fiber laserin order to power up THz output
Observation of THz wave output by an oscilloscope
Chopper
THz wave
THz wave output with high power fiber laser
-
(HPC)
(TPAH)
+H2O,
TPAH+HPC(10:3)
+H2O,
or
50/70
or
50/70
(TPMH)
(TPMH)
1 2 3 4 5
1
2
3
4
0Frequency (THz)
Abso
rban
ce
In situ
XRD(RINT Ultima , Rigaku)CuK: 1050: 0.02
MIR (FT/IR-6300, JASCO)
: 4000-400 cm-1Scan number: 256: 2 cm-1: ATR
NIR (MPA FT-NIR, Bruker)
: 12500-4000 cm-1
Scan number: 32: 2 cm-1:
NIR
Nd:YAGLaser
Cr: Forsterite(signal)
Cr: Forsterite(pump)
GaP e
e
WP CP
RT-DTGS
1064nm
1240-1280nm
1240nm
HM
WP: /2 CP : HM:
(GaP THz Spectrometer, ): Cr:Forsterite : DTGS :0.6 6.1 THz :15GHz:
H2O
HPC
HPC
NIHS
60min
+
120min
TPTPMH0min15min60min120min240min1200min
2.0THz
TPAHTPMH0min15min60min120min240min1200min
NIR7050
4270 cm-1C-Hv(CH) + (CH)
C-H-CH3
C-H-CH3
[N-CH3]
1383cm12887cm1
CH3C-H
C-N
in situ
HPC
HPC
Theophylline monohydrate
X
CH3
2
H2O
ex. 100 m
THz
-
2211
VLSIULSI
PHCAP
1ppt(10-12)
()()()
C=/W (C: pn: W: )
-
411
(PHCAP) Deep Level Transient Spectroscopy (DLTS) Isothermal Capacitance Transient Spectroscopy (ICTS)
(PL)
PHCAP
-
QMC Instruments Ltd.
QNbB/Dry
THz
CW GaP THz Spectrometer
Dry airpurged
Nb TES bolometer
MotorizedLinearStage
Chopper
Lock-inAmp.
MotorizedRotary Stage
Collimator
DFB : Distributed - Feedback laser
ECLD: mode-hop free External Cavity Laser Diode
YbFA: Yb doped Fiber Amplifier Cryostat
DFB
2 channelFrequency Meter
YbFA
ECLD
Powerfeedback
Powerfeedback
Frequency feedback
Nb TES: Nb SuperconductingTransition Edge Sensor
GaPLens
Collimator
Frequency feedback
YbFA
THz wave
Nb TES bolometer
System optical responsivity
System RMS output noise at 80 Hz
System optical NEP at 80 Hz
QMC instruments QNbB/PTC
168 kV/W
430 /
2.6 /
THz
DFG
THz
CW
S/N
1.000000 THz
0.1 7.5 THz
-
J. Nishizawa, Y. Okuno, K. Suto, T. Sato, and S. Yamakoshi 1974 Solid State Commun. 14 889.J. Nishizawa, Y. Okuno 1975 IEEE Trans. Electron Devices ED-22 716.
GaP
,
Time
Tem
pera
ture
Time
Tem
pera
ture
P
GPG T
TPP TG:
TP:
PG:
PP:
eV01.1exp1067.4Torr
B
6GaP Tk
P