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Title
MAT-070
Organic Materials for Non-Linear Optics
Research Objective• Characterize novel organic
materials with tailored optical parameters
• Synthesize both inorganic and organic materials that have large two-photon absorption and/or excited state absorption characteristics across a wide wavelength spectrum
Challenges• No singular material exists that encompasses
broadband nonlinearities required for wide array of Army systems
• Materials need to exhibit large two-photon absorption and/or excited-state absorption cross sections in multiple wavelength bands
• Materials must be color neutral for Army systems
ARL Facilities and Capabilities Available to Support Collaborative Research
Complementary Expertise / Facilities / Capabilities Sought in Collaboration• Density Functional Theory (DFT) modelling of
inorganic compounds and Time-Dependent DFT (TD-DFT) of molecular excited states
S0
S1T1
σT
kisc
σg
Sn
Tn
σ2PA
σS
Z / Z0
Nor
mal
ized
Tran
smitt
ance
t (ps)
Popu
latio
n Fr
actio
n
S1
S2
30-ps FWHM pulsedelivering 380 nJ:27 mJ/cm2 on-axis
• Simulations of experimental data accomplished using in-house MATLAB GUI applications
• Z-scan technique to measure nonlinear absorption and refraction
400 500 600 700 800 900
0.0000
0.0025
0.0050
0.0075
EP-15-04[Ir(pbt)2(acac)]5.0 ns410 nm Exc.
Delta
Abs
orba
nce
Wavelength (nm)
0 1 2 3 4 5
0.0000
0.0025
0.0050
0.0075
Delta
Abs
orba
nce
Time (µs)
EP-15-04 525 nm
τ = 807 ns
O
O
S
N
S
N
Ir
• Visible and near-infrared transient absorption spectrometers to measure excited-state dynamics
Cl
Cl
S
N
S
N
Ir
S
N
S
N
Ir
IrCl3 • 3H2O
S
N
R R
O OH
O
O
S
N
S
N
Ir
O
O
F
F
F
F
F
F
F
F
F
FF
FF
F
F
F
FF
F
F
F
F
F
F
F
F
O
O
N
N
O
O
N
N
5 6 7
O
O
O
O
CF3
CF3
O
O
1 2 3
O
O
4
• UV-Vis spectrometer to characterize linear absorption spectrum
• Synthetic organic chemistry
• Wavelength tunable lasers at different pulsewidth regimes, fs, ps, ns
Five-level model for excited-state absorption
Wavelength Range (nm) Pulse-width (FWHM)Ekspla (1064nm, 1 J) 400 – 2400 3 – 5 nsEkspla (1064nm, 50 mJ) 400 – 2400 25 psEkspla (532nm, 2 mJ) N/A 10 nsFemtoLasers (780nm, 500 mW) N/A 9 fsSpectra-Physics (800nm, 3.5 mJ) 285 – 2800 100 fsCoherent (800nm, 100 mJ) 1160 – 11,000 100 fsPranalytica (QCL, 100mW) 8.1 μm - 12 μm Quasi-CW
S&T Campaign: Materials ResearchPhotonics
Sensor Protection
Trenton R. Ensley(301) [email protected]
• Measure FL quantum yield, 2PA cross-sections, and FL lifetimes
ExcitationMonochromatorXe Lamp
EmissionMonochromator
Tunable 1 kHz, ~100 fs laser source
Sample
300 400 500 600 700 8000.0
0.5
1.0
0 4 8 120.0
0.5
1.0
700 800 900 10000
100
200
300
Nor
mal
ized
Spe
ctra
Wavelength (nm)
AbsFL
FL In
tens
ity (a
.u.)
Delay (ns)
Model ExpDec1
Equation y = A1*exp(-x/t1) + y0Reduced Chi-Sqr
2.08963E-4
Adj. R-Square 0.99663Value Standard Error
Norm
y0 0.00982 7.85726E-4A1 1.01803 0.00198t1 2.51851 0.01012k 0.39706 0.0016tau 1.7457 0.00702
τFL = 2.52 ns
δ 2PA (G
M)
Wavelength (nm)
Rhodamine B in MeOH
