Real-time monitoring of all-optical poling of azo-dye polymer thin film

Abstract

Simultaneous writing and probing of photoinduced second-order susceptibility chi((2)) in an azo-dye polymer thin film is demonstrated. The method is based on the fact that tensor properties of chi((2)) provide different planes of polarization for seeding and signal second harmonics. Our technique allows the chi((2)) 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 chi((2)) in a DR1-PMMA guest¿host system under low seeding intensities is shown.

Real-time monitoring of all-optical poling by two-beam second-harmonic generation

“…Churikov et al have shown that when the polarizations of the writing and seeding beams are not parallel or perpendicular, the seeding and signal second-harmonic beams have different linear polarizations. 12 Thus the seeding beam can be blocked by an analyzer, while part of the signal beam is transmitted and can be detected in real time. However, the technique has some drawbacks.…”

Photochromic azo polysemicarbazides with biocompatibility behavior

“…The transition from trans to cis takes place under ultraviolet light and the reverse variation from cis to trans happens under visible light or kept in the dark [1] . And the trans isomer has an intense absorption due to π-π * transition while the cis isomer shows a weakly absorption of n-π * transition.…”

“…The final product was recrystallized from DMSO and dried in vacuum. Mp: 274 ℃ 1. H NMR (DMSO, ppm): 10.10 (S, 2H, NH), 8.38 (S, 2H, aromatic), 8.04-8.10 (q, 4H, aromatic), 7.72-7.78 (t, 2H, aromatic), 4.50-4.80 (t, 4H, NH 2 ); Anal.…”

Encoding of macroscopic second-order non-linearity via all-optical polar alignment in substituted norbornene polymer thin films

“…After the poling process the seeding SH was cut by a color ®lter and the photoinduced v 2 ws probed by the fundamental beam. The detailed description of the experimental setup can be found elsewhere [7].…”

“…To avoid distortion of the growth curves by frequent interruption of the poling process for probing, we applied simultaneous writing and probing technique described in Ref. [7]. This method proved itself to be more accurate in comparison with traditional alternating writing and probing technique [7].…”