Extraction of Natural Pigment Curcumin from Curcuma Longa: Spectral, DFT, Third-order Nonlinear Optical and Optical...

Area of Science:

• Materials Science
• Optoelectronics
• Photonics
• Natural Products Chemistry

Background:

• Natural pigments are increasingly explored for advanced optical applications.
• Curcumin, extracted from Curcuma longa, is a well-known natural compound with diverse biological activities.
• Understanding the nonlinear optical (NLO) characteristics of natural compounds is crucial for developing novel photonic devices.

Purpose of the Study:

• To extract and characterize curcumin from Curcuma longa.
• To investigate the linear and third-order nonlinear optical (NLO) properties of extracted curcumin.
• To evaluate curcumin's potential for photonics and optoelectronics applications.

Main Methods:

• Curcumin extraction from Curcuma longa.
• Characterization using UV-Visible absorption, FT-IR, Micro Raman, and GC-MS.
• Third-order NLO properties studied via the Z-scan technique with a 405 nm diode laser.

Main Results:

• Curcumin exhibits negative nonlinear index of refraction (self-defocusing) and positive nonlinear absorption coefficient (reverse saturable absorption).
• Measured NLO parameters include n₂ ≈ 10⁻⁷ cm²/W, β ≈ 10⁻² cm/W, χ⁽³⁾ ≈ 2.73 × 10⁻⁷ esu, and γ ≈ 1.67 × 10⁻³¹ esu.
• A low optical limiting threshold of 0.71 mW was observed, supported by quantum mechanical calculations.

Conclusions:

• Curcumin extracted from Curcuma longa possesses significant third-order NLO characteristics.
• The observed optical limiting effect suggests potential for protective optical devices.
• Curcumin is a promising candidate for novel photonics and optoelectronics applications.