Nano Porous Azobenzene Dendron Films for Laser Eye and Sensor Protection

We have developed an innovative lensless optical power limiting system for green region exploiting photoanisotropy of azobenzene films for low power continuous wave and high power nanosecond pulsed lasers (also with picosecond in solutions). It is a promising technique for next generation laser eye and sensor protection. For a practical device application with films we have to optimize the photoanisotropy to reduce the exciting beam power requirement, improve the response time for ultrashort pulse application and explore avenues for broadband response. To address these issues, this SBIR team proposes films of NanoPAD and MesoPAD systems. The NanoPAD system is designed to use nanosize pores to facilitate ease of photoisomerization and orientation of the azobenzene molecules as in a solution. The interaction between the azobenzene and the host polymer is minimized by reducing their contact area. Further decrease in the interaction will be achieved by reducing polymer polarity. The MesoPAD system is designed with free space around azobenzene molecules to make the environment solution-like for fast response. Finally, several azobenzene molecules will be incorporated into both systems for broadband applications. Protection at both low and high power over the entire visible region will be achieved demonstrating Technology Readiness Level 3.