LAUSR

Abstract The present study focuses on determination of spectral and third-order nonlinear optical (NLO) properties of a natural pigment chlorophyll-a have been extracted from the leaves of coriandrum sativum (coriander). The extraction was carried out by a column chromatography technique, is a sensitive method for isolating the natural pigment chlorophyll-a from coriandrum sativum. The spectral characteristics of the natural pigment were examined by UV–Vis absorption, emission and FT-IR spectra, respectively. The concentration of chlorophyll-a in coriandrum sativum was measured to be 48.6 mg/g using UV–Vis absorption spectra. A peak tailed by a valley curve was noted in closed aperture Z─scan technique due to self-defocusing and open aperture Z─scan curve signifies the reverse saturable absorption (RSA) behavior. The existence of RSA in chlorophyll-a was ensured by ground and excited state absorption cross-section. The real and imaginary parts of the third-order NLO susceptibility of chlorophyll-a were found to be the order of 10─15 m2/V2. The natural pigment exhibits a low optical limiting (OL) threshold of 4.22 × 102 W/cm2 under continuous wave laser regime. The experimental results revealed that the natural pigment chlorophyll-a extracted from the leaves of coriandrum sativum is a potential material for photonics and optoelectronics applications.