Simultaneous writing and probing of photoinduced second-order susceptibility χ<sup>(2)</sup> in an azo-dye polymer thin film is demonstrated. The method is based on the fact that tensor properties of χ<sup>(2)</sup> provide different planes of polarization for seeding and signal second harmonics. Our technique allows the χ<sup>(2)</sup> value to be monitored in real time, completely eliminating the distortion of optical poling that can occur in traditional probing configurations. The possibility of attaining high values of χ<sup>(2)</sup> in a DR1-PMMA guest¿host system under low seeding intensities is shown.
© 2000 Optical Society of America
Victor M. Churikov, Meng Feng Hung, and Chia Chen Hsu, "Real-time monitoring of all-optical poling of azo-dye polymer thin film," Opt. Lett. 25, 960-962 (2000)