Study of the Optical Properties of Palm Kernel Oil as a Potential Laser Cooling Medium

Palm kernel oil, widely produced in South South and South East Nigeria, is an agricultural product with potentially useful optical properties for photonic applications. The refractive index, transmittance, and absorption coefficient of a medium determine its suitability for laser beam propagation and cooling applications. This study characterises the optical properties of cold-pressed palm kernel oil samples obtained from processors in Edo State across the ultraviolet-visible spectrum using a UV-Vis spectrophotometer and Abbe refractometer. Refractive index measurements are performed at five wavelengths corresponding to the sodium D-line, helium d-line, and standard spectral lines, enabling computation of the Cauchy dispersion coefficients. Transmittance and absorption coefficient profiles are recorded from 200 to 900 nm. Results indicate that palm kernel oil exhibits a refractive index of 1.463 at 589 nm, with a high transmittance window exceeding 85 percent between 500 and 800 nm. The absorption edge lies at approximately 360 nm. The low absorption and moderate refractive index suggest potential utility as a beam-path medium in low-power photonic experiments. The findings provide a physicochemical baseline for further investigation of bio-based optical media in low-resource photonics laboratories in Nigerian universities. Keywords: optical properties, palm kernel oil, refractive index, transmittance, photonics