Second Harmonic Generation Decay Research Articles

Synthesis and Properties of Novel Nonlinear Optical Polyimide Containing Nitrophenylazoresorcinoxy Group

New Y-type polyimide (4) containing nitrophenylazoresorcinoxy groups as NLO chromophores, which are components of the polymer backbone, was prepared and characterized. Polyimide 4 is soluble in common organic solvents such as N,N-dimethylformamide and dimethylsulfoxide. It shows a thermal stability up to 290°C in thermogravimetric analysis with glass-transition temperature (Tg) obtained from differential scanning calorimetry near 128°C. The second harmonic generation (SHG) coefficient (d 33) of poled polymer film at the 1064 nm fundamental wavelength is around 5.46 × 10−9 esu. The dipole alignment exhibits a thermal stability up to T g, and there is no SHG decay below 130°C due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.

Synthesis and Nonlinear Optical Properties of Novel Y-type Polyurethane Containing Nitroazobenzene Group

Novel Y-type polyurethane 3 containing 4-(4-nitrophenylazo)resorcinoxy groups as nonlinear optical (NLO) chromophores, which constitute part of the polymer backbone, was prepared and characterized. Polyurethane 3 is soluble in common organic solvents such as acetone and N,N-dimethylformamide. It shows thermal stabilities up to 270°C from thermogravimetric analysis with glass transition temperature obtained from differential scanning calorimetry of 102°C. The second harmonic generation (SHG) coefficient (d 33) of poled polymer film at 1064 nm fundamental wavelength is 4.92 × 10−9 esu. Polymer 3 exhibits a high thermal stability even at 8°C higher than T g, and no significant SHG decay is observed below 110°C, which is acceptable for nonlinear optical device applications.

The design, synthesis, and nonlinear optical properties of novel X‐type polyurethane containing dicyanovinylnitroresorcinoxy group with enhanced SHG thermal stability

AbstractNovel X‐type polyurethane 5 containing 4‐(2′,2′‐dicyanovinyl)‐6‐nitroresorcinoxy groups as nonlinear optical (NLO) chromophores, which constitute parts of the polymer backbone, was prepared and characterized. Polyurethane 5 is soluble in common organic solvents such as acetone and N,N‐dimethylformamide. It shows thermal stability up to 280 °C from thermogravimetric analysis with a glass transition temperature (Tg) obtained from differential scanning calorimetry thermogram of around 120 °C. The second harmonic generation (SHG) coefficient (d33) of poled polymer film at 1064‐nm fundamental wavelength is around 6.12 × 10−9 esu. The dipole alignment exhibits a thermal stability even at 5 °C higher than Tg, and there was no SHG decay below 125 °C due to the partial main chain character of the polymer structure, which is acceptable for NLO device applications. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

Synthesis and electro‐optic properties of novel polyurethane containing the nitrophenylazoresorcinoxy group

AbstractA novel Y‐type polyurethane (polyurethane 3) containing 4‐(4‐nitrophenylazo)resorcinoxy groups as nonlinear optical (NLO) chromophores, which constitute part of the polymer backbone, was prepared and characterized. Polyurethane 3 is soluble in common organic solvents such as acetone and N,N‐dimethylformamide. It shows thermal stability up to 270 °C from thermogravimetric analysis with a glass transition temperature obtained from differential scanning calorimetry of 102 °C. The second harmonic generation (SHG) coefficient (d33) of the poled polymer film at 1064 nm fundamental wavelength is 2.06 pm V−1. Polymer 3 exhibits thermal stability up to Tg, and no significant SHG decay is observed below 100 °C, which is acceptable for nonlinear optical device applications. Copyright © 2012 Society of Chemical Industry

Synthesis and characterization of nonlinear optical side-chain polyimides containing the thiadiazole chromophores

Thermally stable second-order nonlinear optical (NLO) polyimides were synthesized using a standard condensation polymerization technique. The polyimides were prepared from 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and pyromellitic dianhydride (PMDA) with two aromatic azo- and diazo-diamine derivatives as the NLO chromophores. The resulting polyimides were characterized by FTIR, 1H-NMR, UV-vis spectroscopies, differential scanning calorimetry, thermogravimetric analysis, and gel permeation chromatography. The weight-average molecular weights of polyimides determined by gel permeation chromatography (GPC) were in the range of 32,100 to 39,300 (Mw/Mn = 1.58–1.74). All the polyimides exhibited an excellent solubility in many of the aprotic polar organic solvents, manifesting that these polyimides offer good processability. The glass transition temperature for the resulting polyimides was in the range of 152 to 194°C and most of them showed high thermal stability. Particularly, the polyimides containing diazo group and PMDA backbone showed an enhanced thermal stability and glass transition temperature. The second harmonic generation (SHG) coefficients (d33) of the poled polyimide films range from 43.71 to 80.49 pm/V at 532 nm. Further, it is noticed that there was no SHG decay below 180°C because of the partial main-chain character of the polyimide structure, which is acceptable for nonlinear optical device applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Synthesis and Properties of Novel Y-type Nonlinear Optical Polyester Containing Dioxynitroazobenzene Group with Enhanced Thermal Stability of Dipole Alignment

New Y-type polyester (3) containing nitrophenylazoresorcinoxy groups as NLO chromophores, which are components of the polymer backbone, was prepared and characterized. Polyester 3 is soluble in common organic solvents such as N,N-dimethylformamide and acetone. It shows a thermal stability up to in thermogravimetric analysis with glass-transition temperature () obtained from differential scanning calorimetry near . The second harmonic generation (SHG) coefficient () of poled polymer film at the 1064 nm fundamental wavelength is around esu. The dipole alignment exhibits a thermal stability even at higher than , and there is no SHG decay below due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.

Synthesis and Nonlinear Optical Properties of Novel T-type Polyurethane Containing Tricyanovinylthiophene

A novel T-type polyurethane 7 containing 1-(2,5-dioxyphenyl)-2-{5-(1,2,2-tricyanovinyl)-2-thienyl}ethene groups as nonlinear optical (NLO) chromophores was prepared and characterized. Polyurethane 7 is soluble in common organic solvents such as DMF and DMSO. Polymer 7 shows a thermal stability up to 270°C from TGA thermogram and the T g value obtained from DSC thermogram is around 155°C. The second harmonic generation (SHG) coefficient (d 33 ) of poled polymer film at 1560 nm fundamental wavelength is 3.56 × 10−9 esu. The dipole alignment exhibits a thermal stability even at 5°C higher than T g , and there is no SHG decay below 160°C due to the partial main-chain character of the polymer structure, which is acceptable for nonlinear optical device applications.

Synthesis and Nonlinear Optical Properties of Novel Y-type Polyester Containing Nitrophenylazoresorcinoxy Group

A new Y-type polyester (3) containing nitrophenylazoresorcinoxy groups as NLO chromophores, which are components of the polymer backbone was prepared. Polyester 3 is soluble in common organic solvents such as N,N-dimethylformamide and acetone. It shows a thermal stability up to 240°C from thermogravimetric analysis with glass-transition temperature (T g ) obtained from differential scanning calorimetry near 116°C. The second harmonic generation (SHG) coefficient (d 33) of poled polymer films at the 1064 nm fundamental wavelength is around 4.63 × 10−9 esu. The dipole alignment exhibits a thermal stability even at 4°C higher than T g , and no SHG decay was observed below 120°C due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.

Synthesis and Properties of Novel Y-type Nonlinear Optical Polyester Containing Tricyanovinylthiazole

A novel Y-type polyester 4 containing 5-methyl-4-{5-(1,2,2-tricyanovinyl)-2-thiazolylazo}resorcinoxy groups as nonlinear optical (NLO) chromophores was prepared and characterized. Polyester 4 is soluble in common organic solvents such as acetone and N,N-dimethylformamide. It shows a thermal stability up to 250°C from thermogravimetric analysis thermogram with a glass-transition temperature (T g ) obtained from differential scanning calorimetry thermogram of around 94°C. The second harmonic generation (SHG) coefficient (d 33 ) of poled polymer film at 1064 nm fundamental wavelength is 8.12 × 10−9 esu. The dipole alignment exhibits a thermal stability even at 6°C higher than T g and there is no significant SHG decay below 100°C due to the partial main-chain character of the polymer structure, which is acceptable for nonlinear optical device applications.

Synthesis and characterization of thermally stable second-order nonlinear optical side-chain polyurethanes containing nitro-substituted oxadiazole and thiazole chromophores

We have newly synthesized nonlinear optical (NLO) active nitro-substituted thiazole and oxadiazole chromophores and condensed with tolylene-2,4-diisocyanate and 4,4′-methylenedi(phenyl isocyanate) to yield a series of polyurethanes. Molecular structural characterization of the resulting chromophores and polyurethanes was achieved by FTIR, UV–vis, 1H NMR and CHN elemental analyzer. The inherent viscosities ( η inh) of polyurethanes measured with an Ubbelohde viscometer were in the range of 0.26–0.30 dl/g. Thermal behavior of polyurethanes was investigated using differential scanning calorimetry and thermogravimetric analysis. The glass transition temperatures ( T g) of the polyurethanes were in the range of 121–192 °C. Thin films of polyurethanes were prepared and achieved molecular orientation by inducing electric field. The change in the surface morphology of polyurethanes films before and after poling was investigated using atomic force microscopy. All the polyurethanes exhibited an excellent solubility in most of the common organic solvents, suggesting that these polyurethanes offered good processability. The second harmonic generation (SHG) coefficients ( d 33) of the poled polyurethanes ranged from 29.7 to 44.2 pm/V at 532 nm. High thermal endurance of the poled dipoles was observed for all the polyurethanes and this was attributed to the formation of extensive hydrogen bonds between urethane linkages. Furthermore, none of the developed polyurethanes showed SHG decay below 115 °C, and this signified their acceptability for nonlinear optical devices.

Synthesis and nonlinear optical properties of novel Y-type polyester containing tricyanovinylthiazolylazoresorcinoxy group with enhanced thermal stability of dipole alignment

Novel Y-type polyester 4 containing 5-methyl-4-{5-(1,2,2-tricyanovinyl)-2-thiazolylazo}resorcinoxy groups as nonlinear optical (NLO) chromophores, which are parts of the polymer backbone, was prepared, and its NLO properties were investigated. Polyester 4 is soluble in common organic solvents such as N,N-dimethylformamide and dimethylsulfoxide. Polymer 4 shows a thermal stability up to 250 °C from thermogravimetric analysis with glass-transition temperature obtained from differential scanning calorimetry of approximately 94 °C. The second harmonic generation (SHG) coefficient (d33) of poled polymer film at 1560-nm fundamental wavelength is 8.12 × 10−9 esu. The dipole alignment exhibits a thermal stability even at 6 °C higher than glass-transition temperature (Tg), and no significant SHG decay is observed below 100 °C due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Synthesis and Properties of Novel T-type Nonlinear Optical Polyurethane Containing Tricyanovinylthienyl Group with Enhanced Thermal Stability of Dipole Alignment

A novel T-type polyurethane 7 containing 1-(2,5-dioxyphenyl)-2-(5-(1,2,2-tricyanovinyl)-2-thienyl)ethenes as NLO chromophores, which constitute part of the polymer backbone, was prepared. Polyurethane 7 is soluble in common organic solvents such as DMF and DMSO. It shows a thermal stability up to <TEX>$270^{\circ}C$</TEX> from TGA thermogram with <TEX>$T_g$</TEX> value obtained from DSC thermogram near <TEX>$155^{\circ}C$</TEX>. The second harmonic generation (SHG) coefficient (<TEX>$d_{33}$</TEX>) of poled polymer film at 1560 nm fundamental wavelength is <TEX>$3.56{\times}10^{-9}$</TEX> esu. Polymer 7 exhibits a thermal stability even at <TEX>$5^{\circ}C$</TEX> higher than <TEX>$T_g$</TEX>, and no significant SHG decay is observed below <TEX>$160^{\circ}C$</TEX>, which is acceptable for nonlinear optical device applications.

Synthesis of Novel Y-type Nonlinear Optical Polyester with Enhanced Thermal Stability of Second Harmonic Generation for Electro-Optic Applications

Methyl 3,4-di-(2'-hydroxyethoxy)benzylidenecyanoacetate (3) was prepared and condensed with terephthaloyl chloride to yield novel Y-type polyester (4) containing 3,4-dioxybenzylidenecyanoacetate groups as NLO-chromophores, which constituted parts of the polymer main chains. The resulting polymer 4 is soluble in common organic solvents such as acetone and N,N-dimethylformamide. Polymer 4 shows thermal stability up to <TEX>$280^{\circ}C$</TEX> in thermogravimetric analysis with glass-transition temperature obtained from differential scanning calorimetry near <TEX>$105^{\circ}C$</TEX>. The second harmonic generation (SHG) coefficient (<TEX>$d_{33}$</TEX>) of poled polymer films at the 1064 nm fundamental wavelength is around 2.42 pm/V. The dipole alignment exhibits high thermal stability up to near <TEX>$T_g$</TEX>, and there is no SHG decay below <TEX>$100^{\circ}C$</TEX> due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.

Synthesis and Nonlinear Optical Properties of Novel Y-Type Polyurethane Containing Cyanovinylthiazole

A novel Y-type polyurethane 4 containing 5-methyl-4-{5-(1,2,2-tricyanovinyl)-2-thiazolylazo}resorcinoxy groups as nonlinear optical (NLO)-chromophores, which constituted parts of the polymer backbones, was prepared and characterized. Polyurethane 4 is soluble in common organic solvents such as acetone and N,N-dimethylformamide. It showed a thermal stability up to 250°C in thermogravimetric analysis thermogram and the glass-transition temperature (T g ) obtained from differential scanning calorimetry thermogram was around 118°C. The second harmonic generation (SHG) coefficient (d 33 ) of poled polymer film at 1560 nm fundamental wavelength was around 8.43 × 10−9 esu. The dipole alignment exhibited a thermal stability even at 12°C higher than T g , and there was no SHG decay below 130°C due to the partial main-chain character of the polymer structure, which is acceptable for nonlinear optical device applications.

Synthesis and Nonlinear Optical Properties of a Novel Polyester Containing Tricyanovinylthienyl Group

A novel T-type polyester (7) containing 1-(2,5-dioxyphenyl)-2-{5-(1,2,2-tricyanovinyl)-2-thienyl}ethene groups as NLO-chromophores was synthesized and characterized. Polymer 7 was soluble in common organic solvents such as DMF and DMSO. It showed thermal stability up to 300°C in TGA with T g value obtained from DSC near 113°C. The second harmonic generation (SHG) coefficient (d 33 ) of poled polymer film at the 1560 nm fundamental wavelength was around 4.42 × 10−9 esu. The dipole alignment exhibited a greater thermal stability even at 10°C higher than T g , and there was no SHG decay below 125°C due to the partial main-chain character of the polymer structure, which is acceptable for nonlinear optical device applications.

Synthesis and Nonlinear Optical Properties of Novel T-type Polyester Containing Thiophene with Enhanced Thermal Stability

A novel T-type polyester 7 containing 1-(2,5-dioxyphenyl)-2-{5-(1,2,2-tricyanovinyl)-2-thienyl}ethenes as nonlinear optical (NLO) chromophores, which are part of the polymer backbone, was prepared and characterized. Polyester 7 is soluble in common organic solvents such as dimethylsulfoxide and N,N-dimethylformamide. It showed a thermal stability up to <TEX>$300^{\circ}C$</TEX> in thermogravimetric analysis thermogram and the glass-transition temperature (<TEX>$T_g$</TEX>) obtained from differential scanning calorimetry thermogram was around <TEX>$113^{\circ}C$</TEX>. The second harmonic generation (SHG) coefficient (<TEX>$d_{33}$</TEX>) of poled polymer films at 1,560 nm fundamental wavelength was around 1.85 pm/V. The dipole alignment exhibits a greater thermal stability even at <TEX>$10^{\circ}C$</TEX> higher than <TEX>$T_g$</TEX>, and there is no SHG decay below <TEX>$125^{\circ}C$</TEX> due to the partial mainchain character of the polymer structure, which is acceptable for nonlinear optical device applications.

Synthesis and nonlinear optical properties of a novel polyurethane containing cyanovinylthiophene with enhanced thermal stability of dipole alignment for electro‐optic applications

AbstractStabilization of electrically induced dipole alignment is one of the important criteria in the development of nonlinear optical (NLO) polymers for electro‐optic device applications. Polyurethanes for NLO applications have attracted attention because of their high thermal stability due to hydrogen bonding. In the work reported here, we designed and synthesized a new type of NLO polyurethane, in which the pendant NLO chromophores are part of the polymer backbone. This mid‐type NLO polymer is expected to have the merits of both main‐chain and side‐chain NLO polymers, namely stable dipole alignment and good solubility. 1‐[3,4‐Di‐(2‐hydroxyethoxy)phenyl]‐2‐(2‐thienyl)ethene was prepared and condensed with 3,3′‐dimethoxy‐4,4′‐biphenylenediisocyanate to yield a polyurethane. This polyurethane was reacted with tetracyanoethylene to give a novel Y‐type polyurethane (7) containing 1‐(3,4‐dioxyphenyl)‐2‐[5‐(1,2,2‐tricyanovinyl)‐2‐thienyl]ethenes as NLO chromophores, which constitute part of the polymer backbone. Polyurethane 7 is soluble in common organic solvents such as N,N‐dimethylformamide and dimethylsulfoxide. It shows a thermal stability up to 280 °C from thermogravimetric analysis with a glass transition temperature obtained from differential scanning calorimetry of ca 162 °C. The second harmonic generation (SHG) coefficient (d33) of a poled polymer film of he polyurethane at 1560 nm fundamental wavelength is ca 1.11 × 10−18 C. Polymer 7 exhibits an enhanced thermal stability and no significant SHG decay is observed below 150 °C, which is acceptable for NLO device applications. Copyright © 2009 Society of Chemical Industry

Development of polyurethanes with azo‐type chromophores for second‐order nonlinear optical applications

AbstractActive nonlinear optical nitro‐substituted thiazole, benzothiazole, and thiadiazole chromophores were prepared and condensed with tolylene‐2,4‐diisocyanate (TDI) and 4,4′‐methylenedi(phenyl isocyanate) (MDI) to yield a series of polyurethanes. The resulting polyurethanes were characterized with Fourier transform infrared, proton nuclear magnetic resonance, and ultraviolet–visible spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and gel permeation chromatography. The weight‐average molecular weights of the polyurethanes ranged between 19,500 and 28,000 (weight‐average molecular weight/number‐average molecular weight = 1.71–2.15). All the polyurethanes exhibited excellent solubility in most common organic solvents, and this indicated that these polyurethanes offered good processability. The glass‐transition temperatures (Tg's) of the polyurethanes were in the range of 166–204°C. Among the polyurethanes, chromophores containing the nitrothiazole moiety exhibited lower Tg values in comparison with those of chromophores containing nitrobenzothiazole and nitrothiadiazole moieties. This was attributed to the small size of the nitrothiazole moiety in the polyurethane matrix. The polyurethanes containing a TDI backbone demonstrated relatively high Tg values in comparison with those of the polyurethanes containing an MDI backbone. This was a result of an enhancement of the rigidity caused by the incorporation of a toluene ring into the polyurethane backbone. The second harmonic generation (SHG) coefficients of the poled polyurethane films ranged from 67.29 to 105.45 pm/V at 1064 nm. High thermal endurance of the poled dipoles was observed for all the polyurethanes. This was attributed to the formation of extensive hydrogen bonds between urethane linkages. Furthermore, none of the developed polyurethanes showed SHG decay below 150°C, and this signified their acceptability for nonlinear optical devices. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Synthesis and Nonlinear Optical Properties of Novel Polyester Containing Tricyanovinylthiophene with Enhanced Thermal Stability of Second Harmonic Generation

A novel Y-type polyester (7) containing 1-(2,4-dioxyethoxy)phenyl-2-{5-(1,2,2-tricyanovinyl)-2-thiophenyl)}ethenyl groups as NLO-chromophores was synthesized and characterized. Polymer 7 was soluble in common organic solvents such as DMF and DMSO. It showed thermal stability up to 300°C in TGA with T g value obtained from DSC near 134°C. The second harmonic generation (SHG) coefficient (d 33 ) of poled polymer film at the 1,560 nm fundamental wavelength was around 6.74 × 10−9 esu. The dipole alignment exhibited high thermal stability and there was no SHG decay below T g due to the partial main-chain character of polymer structure, which was acceptable for NLO device applications.

Synthesis of Novel Y-Type Nonlinear Optical Polyurethane Containing Tricyanovinylthiophene with High Thermal Stability of Dipole Alignment

A novel Y-type polyurethane 7 containing 1-(2,4-dioxyethoxy)phenyl-2-{5-(1,2,2-tricyanovinyl)-2-thiophenyl)}ethenyl groups as nonlinear optical (NLO)-chromophores, which are components of the polymer backbones, was prepared. Polyurethane 7 is soluble in common organic solvents such as DMF and DMSO. It showed a thermal stability up to 280°C in TGA thermogram and the T g value obtained from DSC thermogram was around 163°C. The second harmonic generation (SHG) coefficient (d 33 ) of poled polymer film at 1560 nm fundamental wavelength was around 3.72 × 10−9 esu. The dipole alignment exhibited a thermal stability up to near T g , and there was no SHG decay below 150°C due to the partial main-chain character of the polymer structure, which is acceptable for nonlinear optical device applications.