Airy beams showing curved paths have found extensive applications in fields such as optical trapping, biomedical analysis, and material processing. Despite their utility, dynamic control of Airy beams poses a significant challenge. This work investigates the experimental realization of dynamic steering of Airy beams by utilizing computer-generated holograms with phase-amplitude encoding on a phase-only spatial light modulator (SLM). We successfully generated and controlled Airy beams by imposing dynamic phase masks that manipulated both the phase and amplitude of the field, which sets our approach apart from conventional methods with only phase manipulation. By directly encoding in situ such a hologram and transferring it to an SLM, we are able to control the initial position and rotational orientation of Airy beams without relying on mechanical movement or traditional optical setups involving lenses and apertures. Generating Airy beams in any initial position and rotational direction is anticipated to significantly impact applications such as optical trapping, optical communication, and biomedical imaging by providing a flexible platform for dynamic Airy beam manipulation.

This study investigates how holographically shaped transverse electromagnetic (TEM) laser beam modes can enhance wireless power transmission (WPT) efficiency in nonlinear media. Conventional intracavity methods for generating TEM laser beam modes often reduce electrical-to-laser conversion efficiency. To avoid this limitation, we employed computer-generated holograms on an external spatial light modulator (SLM) to transform an initial Gaussian beam into higher-order modes, including Hermite–Gaussian and Laguerre–Gaussian beams. This approach preserves the intrinsic efficiency of the laser source. Our experiments demonstrate, for the first time, that such beam shaping can significantly improve WPT performance through a nonlinear medium. Nonlinear media refers to materials where the refractive index depends on the intensity of the light, such as pressurized air, nonlinear crystals, or specific liquids. Notably, selected Laguerre–Gaussian modes exhibited transmission gains of up to 12.0% compared with the fundamental mode. These findings provide new insights for designing efficient and robust laser-based energy transfer systems for operation in nonlinear environments.

Some materials can change their electrical polarization under the influence of a mechanical stress due to the piezoelectric effect. This stress-induced change in polarization produces a potential difference across the material. For this reason, the piezoelectric material generates an electrical signal when it is subjected to a pressure from acoustic energy. In this study, analysis of acoustic signals of footsteps from the piezoe-lectric sensor, especially for human footsteps, have been studied by considering the analytical relationship between the electrical signal generated from the sensor and the acoustic signal that provides the effect. We analyzed the acoustic signal data by assuming that the electrical output voltage of the piezoelectric sensor completely coincides with the frequency of the acoustic signals. The original signal was pre-processed using filtering systems and analyzed by the fast Fourier transform and power spectral density methods to extract descriptive spectral features of the signal. This preliminary study proposed a method as a sensor based piezoelectric security system to detect the acoustic signals that can indicate possible dangers to the safety of people or property. The source of the acoustic signal can be determined by matching it with the existing database using machine learning algorithms like face recognition systems for future goals.

This study optimizes the geometric parameters of a circular multi-pass cell (CMPC) to maximize optical absorption path-length using a Taguchi L ₂₇ orthogonal array. Three control factors—inner cell radius ( R ), number of vertices ( p ), and star polygon density ( q )—were evaluated through Signal-to-Noise ratio and ANOVA. Results identify cell radius as the dominant factor, contributing 85.64% to the total variance, followed by p (7.06%) and q (4.49%). A significant interaction between R and p ( P = 0.045) indicates a synergistic effect on beam trajectory. A linear regression model was developed and validated through methane direct absorption spectroscopy at 1651 nm. The experimental path-length deviated by less than 0.5% from the 88.3 m theoretical prediction. These findings provide a robust framework for optimizing CMPC designs in high-sensitivity trace gas detection by precisely quantifying the complex relationships among geometric parameters.