Vibrational spectroscopic, linear and nonlinear optical characteristics of Anthocyanin extracted from blueberry

Abstract

A natural pigment Anthocyanin, extracted from blueberry, has been reported in this paper. The structure of blueberry powder was studied by X-ray diffraction (XRD) and it divulges that the prepared powder seems to be amorphous. Fourier transform infrared (FT-IR) and FT-Raman studies were carried out to recognize the functional groups present in Anthocyanin pigment. Third-order nonlinear optical characteristics of Anthocyanin have been measured using Z-scan technique with a continuous wave diode laser working at the excitation wavelength of 635 nm. Anthocyanin pigment exhibits a negative nonlinear index of refraction and absorption coefficient respectively due to self-defocusing and saturable absorption nature. The nonlinear index of refraction (n2) and nonlinear absorption coefficient (β) of Anthocyanin were measured to be −2.07 × 10−7 cm2/W and −2.19 × 10−3 cm/W respectively. Optical limiting (OL) of Anthocyanin was studied and this exhibits a low limiting threshold of 3.21 × 102 W/cm2. Figure of merit (FOM) conditions were verified for all-optical switching device applications. The present experimental results suggest that the natural pigment Anthocyanin may be a promising material for photonics and optoelectronics applications.