Aging in second-order nonlinear optical polymers

Photonic communications technology is revolutionizing the way we transmit and receive information (higher speeds, lower costs). Second-order nonlinear optical (NLO) polymers may play a role in this revolution if adequate stability, optical nonlinearity and low loss can be demonstrated. The thermal stability of NLO polymer films has been dramatically improved in recent years by binding the chromophores to aromatic polyimides and other stiff backbones having glass transition temperatures (T g s) over 200°C, and by crosslinking the polymers. The long-term chemical stability problem (especially photoinduced oxidation) needs more study; however, by proper choice of the chromophore for the optical frequencies of device operation, and by improving device packaging, these problems can be successfully mitigated. This review summarizes aging studies on NLO polymers from about 1993 through 1996.