Vol. 16 No. 2 (2024)

In this issue, seven papers are presented, highlighting the advancements in optical and photonic technologies, demonstrating their potential in environmental monitoring, high-power applications, medical diagnostics, industrial metrology, and optical fiber sensors. Specifically, the critical points of the papers are: (i) investigations on input parameters of optical scattering, particle size and material, excitation laser, and refractive index of the medium, assisted by machine learning aimed particle characterization concerning microplastic pollution; (ii) development of a laser system dedicated to high-power applications and based on an in-house developed Yb3+ doped silica fiber with a large core, achieving a maximum output power of 107 W; (iii) design of a Photonic Crystal Fiber (PCF) sensor, leveraging guided-mode resonance and integrating a specific biomarker, for accurate and early-stage detection sensitive of tumor cells in cerebrospinal fluid; (iv) application of short wavelength infrared absorption spectroscopy for detecting methane and ammonia, addressing the current needs of industrial gas metrology; (v) proposal and verification of the method for modeling the emission of yellow phosphor YAG:Ce3+ based on the Gaussian function; (vi) a concept and numerical analysis of a fast scanner that combines a planar waveguide with a grating coupler and a swept source laser to be applied in PICs, (vii) a new method for fabricating fiber optic sensors based on D-shape fibers with an elliptical core. This innovative approach maintains a polarized state and enhances the performance of optical fiber sensors.