Nonlinear optical chromophores

The material system is a Langmuir-Blodgett film of the S enantiomer of a chiral polymer deposited on a glass substrate. The polymer is a poly(isocyanide)30 functionalized with a nonlinear optical chromophore (see Figure 9.14). In this particular system the optical nonlinearity and chirality are present on two different levels of the molecular structure. The chirality of the polymer is located in the helical backbone whereas the nonlinearity is present in the attached chromophores. Hence, this opens the possibility to optimize both properties independently. 

Liao, Y. Anderson, C. Y. Sullivan, P. A. Akelaitis, A. J. P. Robinson, B. H. Dalton, L. R., Electro optical properties of polymers containing alternating nonlinear optical chromophores and bulky spacers, Chem. Mater. 2006, 18, 1062 1067... 

R, R. Tykwinski, U. Gublei R, E. Martin, F. Diederich, C. Bosshard, P. Gunter, Structure-Property Relationships in Third-Order Nonlinear Optical Chromophores , J. Phys. Chem B. 1998,102, 4451-4465. 

The values of the second-harmonic coefficient, d33, for samples 5-9 are listed in Table II. The values of d33 were obtained using the analysis of Jerphagnon and Kurtz (25), and were calculated under the assumption that the degree of alignment of the nonlinear optical chromophores can be described using the isotropic model. Hence, we assumed d33=3d31 (4). 

D. Nonlinear Optical Chromophores and Refractive Index Modulation... 

The generic experiment in hyper-Rayleigh scattering4 consists of measuring the intensity of the second harmonic l(2a>) that is scattered by a fundamental laser beam impinging on a solution of nonlinear optical chromophores in a suitable solvent. This intensity should be quadratically dependent on the fundamental intensity l(o>). 

The use of femtosecond pulses in nonlinear optics has one obvious advantage high peak power, necessary to observe the nonlinear effect, can be obtained from low total power in the pulse. This made samples with a low damage threshold amenable for HRS measurements. One example of such sample is amorphous polymer films. These films do not have the optical quality of single crystals. They are more susceptible to optical damage. With the femtosecond pulses, we have been able to perform HRS measurements on solid thin films, to study the orientational correlation between nonlinear optical chromophores in the film.10 13... 

Bosch M, Fischer C, Cai C, Liakatas I, Jager M, Bosshard Ch, Gunter P (1999) Photochemical stability of highly nonlinear optical chromophores for electro-optic applications. In Organic thin films for photonics applications. Optical Society of America, Washington DC, p 75... 

Kaatz, P. and Shelton D.P., Polarized hyper-Rayleigh light scattering measurements of nonlinear optical chromophores. J. Am. Chem.SOc. (1996) 105 3918-3929. 

Considerable effort has been expended upon investigating the electronic absorption and fluorescence properties of carbazole derivatives or molecules containing a carbazole moiety/substructure, due to the interest of these compounds for application as nonlinear optical chromophores and as photoconducting materials. In the following, selection of papers is guided mainly by criteria of structural relevance, omitting very bulky molecules in which the carbazole unit is not prominent, or studies of luminescence properties. An overview of the electronic absorption spectra of carbazole derivatives is provided in Table 24. 

Reaction of indole with l,3-dioxolan-2-one leads to 2-(l//-indol-l-yl)-l-ethanol 134 (Equation 24) <2001PLM3023>. Indole 134 was used in the synthesis of a photoconducting nonlinear optical chromophore, 2-[3-(6-nitro-l,3-benzoxazol-2-yl)-lf/-indol-l-yl]-l-ethanol. 

Two crosslinkable perfluorinated bisphenol A polymeric derivatives having nonlinear optical chromophores containing thiophene have been prepared. Both crosslinked polymers had higher Tg s and greater mechanical stability than their noncrosslinked analogues and were used as light-emitting diodes. 

The preparation of the Step 3 crosslinking nonlinear optical chromophore coreagent is described by Huang [1]. Additional crosslinkable luminescent agents, (I) are provided below, (I). 

Title Polymers Having Pendant Nonlinear Optical Chromophores and Electrooptic Devices Therefrom... 

A polymer containing the nonlinear optical chromophore trans-2,2 -formyl-3,3, -4,4 -tetrabutoxyvinylthiophene was prepared and proved is effective as a waveguide. 

Additional Step 12 polymeric nonlinear optical chromophores and electrooptic devices were prepared by the author [1] in earlier investigations. 

Compositions comprising a crosslinkable perfluoro poly(aryl ether), (1), and a nonlinear optical chromophore were prepared by the author [2] and Chen [3]. 

An additional nonlinear optical copolymer derivative, (I), plasticizer, (11), and nonlinear optical chromophore, (111), were also prepared. 

In earlier investigations by the author [1,2] an additional nonlinear optical chromophore, (IV), and charge transport agent, (V), respectively, were prepared and used in photorefractive applications. 

---