Nonlinear Optical Features of Phenol Red Dye in Different Solvent Media Using Z-scan and Density Functional Theory.

Area of Science:

• Nonlinear optics
• Materials science
• Photophysics

Background:

• Phenol red dye is a common pH indicator.
• Understanding its nonlinear optical (NLO) properties is crucial for applications in photonics and optical devices.
• Solvent effects can significantly alter the NLO behavior of organic molecules.

Purpose of the Study:

• To investigate the third-order nonlinear optical properties of phenol red dye in various polar solvents.
• To determine key NLO parameters such as nonlinear refractive index and absorption coefficient.
• To explore the influence of solvent-specific and non-specific interactions on the dye's NLO response.

Main Methods:

• Experimental characterization using fluorescence spectroscopy and Z-scan technique with a 405 nm diode laser.
• Theoretical calculations employing Density Functional Theory (DFT) at the B3LYP/6-311+G(d,p) level.
• Multi-parameter scale analysis to assess solvent impact.

Main Results:

• Phenol red dye shows excitation in the red spectrum and possesses a large second-order hyperpolarizability (order of 10⁻³¹ esu).
• Nonlinear refractive index and absorption coefficient were determined to be of the order 10⁻⁷ cm²/W and 10⁻² cm/W, respectively.
• DFT calculations supported experimental findings for linear and hyperpolarizability values (α, β, γ) in ethanol, methanol, DMF, and DMSO.

Conclusions:

• Phenol red dye displays significant nonlinear optical properties, making it a candidate for NLO applications.
• Both specific and non-specific solvent-solute interactions play a role in modulating the observed nonlinear optical effects.
• The study provides valuable experimental and theoretical data for understanding and utilizing phenol red dye in optical materials.