Temperature-dependent fluorescence peak shift in ruby using pulsed fiber laser heating

Abstract

Ruby crystals emit fluorescence under UV excitation, and its spectral response is known to be sensitive to external factors such as temperature, pressure, and mechanical stress. In this study, we investigated the temperature-dependent fluorescence of a ruby crystal to evaluate its suitability for non-contact thermometry. The crystal was excited using a UV laser diode, while its temperature was controlled using pulsed fiber laser heating. Fluorescence spectra were collected using an Ocean Optics spectrometer and analyzed through double Gaussian fitting of the normalized data. The extracted R₁ and R₂ peak wavelengths were plotted against temperature, and linear regression yielded peak wavelength shifts of 0.0050 nm°C⁻¹ and 0.0041 nm°C⁻¹, respectively. A 95% prediction interval was computed to visualize the data spread and assess potential outliers. The results support the potential of ruby as a suitable material for non-contact temperature sensing applications.