Design and synthesis of a thermally stable second‐order nonlinear optical chromophore and its poled polymers

Abstract

A multiple charge‐transfer second‐order nonlinear optical (NLO) chromophore 2,3‐bis(4‐aminophenyl)‐5,6‐dicyanopyrazine (BAPDCP) was successfully designed and synthesized. It was characterized by 1H NMR, mass spectrometry, Fourier transform infrared spectroscopy, and elemental analysis. The first hyperpolarizability β of BAPDCP was measured with the Hyper–Rayleigh scattering technique, which was 123.5 × 10−30 esu. The donor‐embedded prepolyimide and prepolyurea were also synthesized by a polyaddition reaction. Thermogravimetric analysis and differential scanning calorimetry demonstrated that either the chromophore or the polymers have fine thermal stability. The thin films of prepolymers were prepared by coating on ITO glass substrate and poled by corona poling at elevating temperature. The second‐order NLO coefficients d33 of the films were measured by in situ second‐harmonic generation measurements. The d33 were deduced as 27.7 and 16.5 pm/V for polyurea and polyimide at 1064 nm fundamental wavelength, respectively. The onset depoling temperature of the polyimide and polyurea were both as high as 200 °C. To understand the temperature effect to the orientation thermal stability of polyimide, two films were treated at different final poling temperatures. The depoling experimental results showed that the orientation stability is higher, as raising the final treated temperature but the d33 value are almost similar. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2846–2853, 2003

Nonlinear optical polyimide/montmorillonite nanocomposites consisting of azobenzene dyes

“…The mixture was heated at 70 C for 48 h and then dried in a vacuum oven at 70 C. The obtained mixture was extracted by chloroform for 24 h using a Soxhlet extractor and dried under vacuum at 70 C. Yield: 81.2%. 1 Poly(amic acid) (PAA) was synthesized by placing 2,2-bis(3-amino-4-hydroxypheny1)-hexafluoropropane (0.36626 g, l mmol) in 5 ml of dried DMAc in a 50 ml flask. After the diamine was dissolved completely, 4,4 0 -oxydiphthalic anhydride (0.3257 g, 1.05 mmol) was added to the diamine solution in one portion.…”

“…Yield: 86.3%. 1 4-((4 0 -Nitrophenyl)azo)phenylisocyanate was synthesized by reacting Disperse Orange 3 (DO3) dye with triphosgene. DO3 (0.738 g, 3 mmol) was dissolved in 50 ml of dried toluene in a 250 ml flask and heated at 100 C. After DO3 was dissolved completely, triphosgene (0.297 g, 1 mmol) was added to the DO3 solution in one portion.…”

“…Second-order nonlinear optical (NLO) polymers have been extensively studied for applications in optical communication, optical data storage, optical switching and frequency modulation because of their large optical nonlinearity, fast response, and easy processing for integrated assembly [1,2]. Large optical nonlinearity, excellent temporal stability of dipole orientation, and low optical loss are important challenges to material scientists in designing second-order NLO materials [3,4].…”

Synthesis and characterization of azo‐based acrylate polymers for use as nonlinear optical materials

“…1,2 All the research carried out in nonlinear optics aims at developing a material with good nonlinear properties and satisfying all the technological requirements such as fast response, high damage threshold, and wide transparency range. 3,4 Organic polymers are better choice for NLO applications when compared to the inorganic crystal.…”

Preparation and characterization of the soluble NLO polyarylates with enhanced electro-optic properties

“…Recently, the organic polymeric nonlinear optical (NLO) materials have attracted much attention due to their large electro optic coefficients, ultralow re sponse times and easy processability in EO devices such as telecommunications, optical data storage, and optical information processing [1,2]. For the practical applications, the NLO materials should meet mainly three requirements: large macroscopic optical non linearity, high temporal stabilities and good optical transparency [3].…”