The Relationship Between Second-Order Nonlinear Optical Properties And Ground-State Polarization

1993 ◽  
Vol 328 ◽  
Author(s):  
Grant Bourhill ◽  
Lap-Tak Cheng ◽  
Ging Lee ◽  
Seth R. Marder ◽  
Joseph W. Perry ◽  
...  
Keyword(s):  
Ground State ◽  
Second Harmonic ◽  
Solvent Polarity ◽  
Second Order ◽  
X Ray Diffraction ◽  
H Nmr ◽  
Electro Optic ◽  
Theoretical Predictions ◽  
Donor Acceptor ◽  
The Relationship

ABSTRACTA review is presented describing our recent work to correlate the first hyperpolarizability, β, of organic materials with the molecular parameter bond length alternation (BLA). Donor-acceptor polyenes displaying a wide BLA range were synthesized. For a particular chromophore, BLA was fine-tuned by varying solvent polarity. The degree of BLA was analyzed by X-ray diffraction, 1H-NMR and electronic absorption spectroscopy. Non-resonant, solvent-dependent, electric field induced second harmonic generation (EFISH) Measurements were performed to probe the variation in the second-order nonlinearity as a function of ground-state polarization. The resulting trend, which is fully consistent with theoretical predictions, identified chromophores possessing optimized positive and negative hyperpolarizabilities. An optimized chromophore was incorporated in a polymer matrix and poled. The resulting electro-optic coefficient was found to be significantly enhanced relative to the longer chromophore Disperse Red 1.

TERAHERTZ OPTICAL RECTIFICATION

1995 ◽  
Vol 04 (02) ◽  
pp. 459-495 ◽  
Author(s):  
Y. H. JIN ◽  
X.-C. ZHANG
Keyword(s):  
Second Harmonic ◽  
Difference Frequency Generation ◽  
Nonlinear Process ◽  
Second Order ◽  
Optical Rectification ◽  
Temperature Dependent ◽  
Optical Absorption Band ◽  
Sum Frequency ◽  
Electro Optic ◽  
Frequency Generation

We present experimental measurements of Terahertz optical rectification in electro-optic crystals. The measured data was compared with a simple theoretical analysis (anharmonic oscillator model). We also measured Terahertz-bandwidth subpicosecond electromagnetic radiation via nearly-degenerate difference-frequency generation in electrooptic materials. The variation in Terahertz emission with crystal orientation demonstrated that the generation of Terahertz radiation via optical rectification involves a bulk second-order nonlinear process. We studied Terahertz optical rectification from zincblende crystals as the incident photon energy was tuned across the semiconductor optical absorption band-edge (resonant excitation). We also present the measurement of temperature-dependent Terahertz optical rectification. A comparison between the two second-order nonlinear processes, sum-frequency generation (second-harmonic generation) and different-frequency generation (optical rectification) is presented.

Light induced intramolecular energy and electron transfer events in carbazole–corrole and phenothiazine-corrole dyads

2020 ◽  
Vol 24 (05n07) ◽  
pp. 693-704
Author(s):  
B. Shivaprasadachary ◽  
A. R. Ramya ◽  
Govind Reddy ◽  
L. Giribabu
Keyword(s):  
Electron Transfer ◽  
Energy Transfer ◽  
Ground State ◽  
Transfer Rates ◽  
Fluorescence Studies ◽  
H Nmr ◽  
Quenching Efficiency ◽  
Energy And Electron Transfer ◽  
Donor Acceptor ◽  
Photo Induced Electron Transfer

We report two corrole based donor–acceptor (D–A) dyads, Cbz-Cor and Ptz-Cor to understand the energy/electron transfer reactions. In these D–A systems, the donor, either carbazole (Cbz) or phenothiazine (Ptz), is covalently connected at the meso-phenyl position of 10-(phenyl)-5,15-bis-(pentafluorophenyl)corrole (Ph-Cor) by C–N linkage. Both the dyads were characterized by 1H NMR, MALDI-TOF MS, UV-vis, electrochemical, computational methods, study state fluorescence and TCSPC techniques. A comparison of absorption spectra with their reference monomeric compounds (Cbz-Ph, Ptz-Ph and Ph-Cor) revealed minimal ground-state interactions between chromophores in both dyads. Fluorescence studies suggested that singlet–singlet energy transfer from 1Cbz* to corrole is the major photochemical pathway in the Cbz-Cor dyad with a quenching efficiency of [Formula: see text]99%. Detailed analysis of the data suggests that Forster’s dipole–dipole mechanism does not adequately explain this energy transfer. However, at a 410 nm excitation, florescence quenching is detected in Ptz-Cor (49%) supporting a photo induced electron transfer (PET) process from the ground state of PTZ to the excited state of corrole macrocycle. The electron-transfer rates ([Formula: see text] of Ptz-Cor are found in the range [Formula: see text] to [Formula: see text] and are concluded to be solvent dependent.

Fused, Three-Ring Donor-Acceptor Molecules as Potential Materials for Efficient Second Harmonic Generation

1989 ◽  
Vol 173 ◽  
Author(s):  
Malcolm R. McLean ◽  
Mamoun Badr ◽  
Larry R. Dalton ◽  
Robert L. S. Devine ◽  
William H. Steier
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Crystal Habit ◽  
Organic Crystals ◽  
X Ray Diffraction ◽  
Ring Compounds ◽  
Donor Acceptor ◽  
Linear Optical Properties ◽  
Corona Poling

ABSTRACTA series of fused three-ring compounds have been synthesized and characterized for their possible use as organic crystals for second-harmonic generation. Polymer films doped with these compounds were aligned via corona poling and their second order non-linear optical properties compared with layers doped with stilbene like molecules. Values of ¼β0 have been obtained and the effects of different heteroatoms and substituents on λ max and on ¼β0 were examined. An X-ray diffraction crystal structure on one member of the series, 1,2,4-Trichloro-8-nitro-phenoxazin-3-one (Compound 1), revealed a centrosymmetric crystal habit in a P21/n space group, with a = 9.829(3), b = 8.300(2) and c = 15.542(4) Å. Final R(F) = 0.0939 for 754 reflections where I σ; 3σ(I).

Theoretical study on naphthyl-phenylacetylenes for second-order nonlinear optical applications

1997 ◽  
Vol 75 (7) ◽  
pp. 1041-1046 ◽  
Author(s):  
B.V.V.S.N. Prabhakara Rao ◽  
D.C. Dube ◽  
D.P. Tewari ◽  
S.C. Mathur ◽  
M. Banerjee
Keyword(s):  
Ground State ◽  
Nonlinear Optical ◽  
Organic Molecules ◽  
Theoretical Study ◽  
Dipole Moments ◽  
Second Order ◽  
Donor Acceptor ◽  
Optical Applications ◽  
Nonlinear Optical Applications ◽  
Ground State Dipole Moments

The ground state dipole moments (μg), excited state dipole moments (μe), linear polarizabilities (α), first hyperpolarizabilities (β), and absorption maxima [Formula: see text] of a new series of 6,4′-disubstituted 2-naphthylphenylacetylenes have been calculated using the finite field – MNDO (Modified Neglect of Diatomic Overlap) technique and studied for second-order nonlinear optical (NLO) applications. Among all the molecules studied here, the strongest and the weakest electron donor/acceptor pairs [N(CH3)2/NO2] and [CH3/CN] exhibit the largest and the smallest βμ (projection of β on the axis of the μ) of 46.3 × 10−30 esu and 10.2 × 10−30 esu, respectively. The coefficients of the power law that describes the dependence of α and β on the number of conjugated bonds (n) were calculated for [NH2/NO2]n=1–5 and [NH2/CN]n=1–5 molecules. For β, exponents of 0.36 and 0.31 were obtained for [NH2/NO2]n=1–5 and [NH2/CN]n=1–5 molecules, respectively, and for α, an exponent of 0.37 was obtained for both series of molecules. A comparison is made between naphthylphenylacetylenes and diphenylacetylenes on the basis of their hyperpolarizabilities. Keywords: nonlinear optics, organic molecules, hyperpolarizabilities.

THE INVESTIGATION OF SECOND-ORDER NONLINEAR OPTICAL PROPERTIES OF P-NITROPHENYLAZOANILINE: SECOND HARMONIC GENERATION AND AB INITIO COMPUTATIONS

2012 ◽  
Vol 11 (01) ◽  
pp. 209-221 ◽  
Author(s):  
ASLI KARAKAŞ ◽  
ZİYA ERDEM KOÇ ◽  
MICHAELA FRIDRICHOVÁ ◽  
PETR NĚMEC ◽  
JAN KROUPA
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Second Harmonic ◽  
Second Order ◽  
Photon Absorption ◽  
Nlo Properties ◽  
Hartree Fock ◽  
H Nmr

p-nitrophenylazoaniline (1) belongs to the family of compounds with conjugated bonds and delocalized π-electrons, structurally similar to the well known push-pull compound Disperse Red 1 (DR1).1 Due to the assembly of the molecule, nonlinear optical (NLO) properties are expectable and can be more or less accurately predicted. To estimate the potential for second-order NLO properties, the electric dipole moment (μ), dispersion-free dipole polarizabilities (α) and first hyperpolarizabilities (β) have been determined by density functional theory (DFT) quantum chemical calculations at B3LYP/ 6-311 + G(d, p) level. According to the computation results, the synthesized compound exhibits non-zero β values and it might have second-order NLO behavior. Title compound has been synthesized and characterized by FT-IR, 1H-NMR and UV-Vis spectroscopies. The maximum one-photon absorption (OPA) wavelengths were estimated to be shorter than 450 nm by quantum mechanical computations using the configuration interaction (CI) method. The same result was achieved by UV-Vis spectra measurements, whereas the compound exhibited good optical transparency to the visible light. Quantitative measurements of second harmonic generation (SHG) at 800 nm and 1064 nm have been performed. The relative efficiency comparable with that of KDP (kalium diphosphate) has been observed with the exciting wavelength of 1064 nm, while the other wavelength led to strong absorption of produced light by the sample. In the following more detailed study on frequency-dependent first hyperpolarizabilities using time-dependent Hartree–Fock (TDHF) method have been computed at the wavelengths used in SHG measurements.

NEW TRIMETHYLAMMONIUM DERIVATIVES TOWARD SECOND-ORDER NONLINEAR OPTICS

2005 ◽  
Vol 14 (03) ◽  
pp. 357-365 ◽  
Author(s):  
ZORNITZA GLAVCHEVA ◽  
HIROHITO UMEZAWA ◽  
SHUJI OKADA ◽  
HACHIRO NAKANISHI
Keyword(s):  
Nonlinear Optics ◽  
Second Harmonic Generation ◽  
Crystal Structures ◽  
Benzene Ring ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Second Order ◽  
Pm3 Method ◽  
Ionic Compounds ◽  
The Relationship

In order to find new ionic compounds with good characteristics for second harmonic generation (SHG), the relationship between first hyperpolarizabilities (β) and the position of the cationic center with respect to the benzene ring was investigated. The β values of a series of trimethylammonium cations: X–C 6 H 4–( CH 2)n N +( CH 3)3, where X = H , CH 3, OCH 3, NH 2, and N ( CH 3)2; n = 0–2, were calculated by using the MOPAC PM3 method. Relatively large calculated β values were obtained when X = N ( CH 3)2 and X = NH 2. Series of [4-(dimethylamino)phenyl]trimethylammonium ( X = N ( CH 3)2; n = 0) and [2-(4-aminophenyl)ethyl]trimethylammonium ( X = NH 2; n = 2) derivatives were synthesized. Among them, seven SHG-active complexes were found and four crystal structures were determined.

Second-Order Nonlinear Optical Properties Of Thiophene Containing Chromophores With Extended Conjugation

1993 ◽  
Vol 328 ◽  
Author(s):  
Sandra Gilmour ◽  
Alex K-Y. Jen ◽  
Seth R. Marder ◽  
A. Jennifer-Neissink ◽  
Joseph W. Perry ◽  
...  
Keyword(s):  
Optical Properties ◽  
Methyl Methacrylate ◽  
Charge Separation ◽  
Nonlinear Optical ◽  
Second Order ◽  
Nonlinear Optical Properties ◽  
Acceptor Group ◽  
Electro Optic ◽  
Phenyl Rings ◽  
Donor Acceptor

ABSTRACTThe synthesis and first hyperpolarizabilities (β) of various donor-acceptor substituted thiophene containing compounds with extended conjugation are reported. Results indicate that replacing phenyl rings with less aromatic thiophene moieties enhances the second-order hyperpolarizability. Incorporating the acceptor group, N,N' diethylthiobarbituric acid, that can gain aromaticity upon charge-separation has also led to an increase in the nonlinearity. Some of the molecules have been incorporated into poIy (Methyl Methacrylate) and the electro-optic coefficients of these host-guest polymers were Measured.

Second-order nonlinear optical properties of polyphosphazenes containing multi-dipolar and imidazolebased chromophores

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Pan Yang ◽  
Tang Xiaozhen
Keyword(s):  
Nonlinear Optical ◽  
Second Harmonic ◽  
Coupling Reaction ◽  
Second Order ◽  
Azo Coupling ◽  
H Nmr ◽  
New Type ◽  
Ft Ir ◽  
Nlo Chromophores ◽  
Second Order Nonlinearity

AbstractThe synthesis and second-order nonlinearity study of several new polyphosphazenes were described, which are composed of a new type of Yshaped nonlinear optical (NLO) chromophores attached onto polyphosphazene. They were obtained via a post-azo coupling reaction. The resulting materials were characterized by means of 1H NMR, 31P NMR, FT-IR, UV-vis, GPC and DSC. Chromophore contents up to 14 mol% have been realized. The polymers have high glass-transition temperatures, good optical transparency, and the poled film of P3- P8 revealed a resonant d33 value in the range of 11-42 pm/V by second harmonic generation (SHG) measurements.

Highly Ordered Pseudo-Discotic Chromophore Systems for Electro-Optic Materials and Devices

2004 ◽  
Vol 846 ◽  
Author(s):  
Nishant Bhatambrekar ◽  
Scott Hammond ◽  
Jessica Sinness ◽  
Olivier Clot ◽  
Harry Rommel ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Second Harmonic ◽  
Photonic Devices ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Discotic Liquid Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dipole Interactions ◽  
Electro Optic

ABSTRACTIn order to achieve the near-ferroelectric order desired in organic electro-optic (EO) chromophore systems, a pseudo-discotic chromophore is under investigation. Calculations suggest head-to-tail inter-chromophore dipole-dipole interactions should drive chromophores with an appropriate aspect ratio into ferroelectric columns similar to those seen in discotic liquid crystals (DLCs). Therefore, the liquid crystalline properties of these chromophores are being examined by differential scanning calorimetery (DSC), polarized optical microscopy (POM), and X-ray diffraction (XRD). Furthermore, the effect of this discotic behavior on the order and EO properties of the system are being examined both dynamically by second harmonic generation (SHG) and statically by attenuated total reflection (ATR). Additionally, these chromophores are being incorporated into waveguide-based photonic devices.

Theoretical Prediction of the Donor/Acceptor Site-Dependence on First Hyperpolarizabilities in Conjugated Systems Containing Azomethine Bonds

1992 ◽  
Vol 291 ◽  
Author(s):  
Azuma Matsuura ◽  
Tomoaki Hayano
Keyword(s):  
Considerable Effect ◽  
Acceptor Site ◽  
Pockels Effect ◽  
Conjugated Molecules ◽  
No Donors ◽  
Electro Optic ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Site Dependence ◽  
The Relationship

ABSTRACTWe calculated frequency-dependent first hyperpolarizabilities for electro-optic Pockels effect, β(ω; 0, ω), in π-conjugated molecules containing azomethine bonds using the CNDO/S-CI sum-over-states method. First, we examined the dependence of static β on formulas for the two-center Coulomb integral, γAB. The choice of the γAB formula has little effect on the relative β value, but a considerable effect on the absolute value. Then we investigated the relationship between the magnitude of β(ω; 0, ω) and the donor/acceptor substitution sites. We found that the molecule with no donors or acceptors can be divided into donor and acceptor regions whose existence causes the donor/acceptor site-dependence of β(ω; 0, ω).

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