Elucidating the Potential of Nonlinear Optical Behavior of Azo Dyes for Advanced Laser‐Based Technologies

Abstract

Organic nonlinear optical materials have received immense attention owing to their extensive applications in optoelectronics and photonics. Nonlinear optical (NLO) materials are significant components of data processing devices, optical computing, optical fibers, modulators, sensors, ultra‐fast switches, and optical storage devices. Therefore, an effort is made to explore the electronic and NLO response of commercially available azo dyes such as Tartrazine (E102), Yellow 2G (E107), Sunset Yellow (E110), Azorubine (E122), Amaranth (E123), Ponceau 4R (E124), and Allura Red (E129) using density functional theory. Frontier molecular orbital analysis reveals that the azo dyes’ energy gap (E_H‐L) ranges from 5.30 to 6.88 eV. E122 contains the narrowest bandgap of 5.30 eV compared to others. The total density‐of‐state and noncovalent interactions analyses confirm the charge transfer and type of interactions in various regions of the azo dyes. Molecular electrostatic potential maps reveal that the azo dyes are involved in significant charge distribution regions favourable for the enhancement of NLO response. Moreover, the highest first hyperpolarizability (β_o3ggn ) value of 4184.87 au is also observed for E122, making it a better candidate for high‐performance NLO material than others. Therefore, these results may advance the development of NLO materials for efficient laser‐based technologies.