Organic sol-gel materials for second-order nonlinear optics based on melamines

✍ Scribed by Ging-Ho Hsiue; Rong-Ho Lee; Ru-Jong Jeng

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 189 KB
• Volume: 37
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19990715)37:14<2503::aid-pola24>3.0.co;2-#

✦ Synopsis

A series of all organic nonlinear optical (NLO) sol-gel materials based on melamines and an azobenzene dye (Disperse Orange 3; DO3) have been investigated. Different contents of DO3 were covalently bonded with the melamine-based organic network via condensation of amino and methylol groups. The optically clear samples exhibited second-order optical nonlinearity (second-harmonic coefficient d 33 ) ϭ 35.4 and 11.5 pm/V at 1064 and 1542 nm, respectively) after poling and curing at 220°C for 1 h. Thermal behavior of these organic NLO sol-gel systems was studied by temperature-dependent dielectric relaxation. The results indicate that the incorporation of rigid NLO-active chromophore into the melamine-based matrix leads to high rigidity and dense packing of the organic network. Subsequently, higher glass transition temperatures were obtained for the organic NLO sol-gel material with higher DO3 content. The influence of composition on the temporal stability at 100°C was also investigated. Temporal stability at 100°C was studied as a function of system composition.