The study of vortex dynamics, an intriguing aspect of science, has made significant strides in areas ranging from gravity studies to fluid movement. In optics, the concept of optical vortices, emerging in the late 1980s, has spurred a variety of applications in fields as diverse as particle manipulation, secure communications, and biosciences. These advancements have been boosted by the development of new photonic technologies, notably spiral phase plates, enabling the creation of a series of optical vortices. These vortices, generated through diffractive optical elements (DOEs) like vortex lenses, are now at the forefront of optical trapping systems, enhancing flexibility and capacity for manipulating tiny particles. The study introduces a spatially multiplexed vortex phase mask, a novel approach that allows for the creation of simultaneous concentric optical vortices, each serving as a unique system for trapping and manipulating particles.

In this pioneering work, lead scientist Francisco Muñoz-Pérez from Universitat Politècnica de València, together with his distinguished team comprising Dr. Vicente Ferrando, Dr. Juan Castro-Palacio, Dr. Ricardo Arias-Gonzalez, and Dr. Juan Monsoriu, all hailing from Universitat Politècnica de València, and Professor Walter Furlan from Universitat de València, has achieved a significant breakthrough in the world of optical tweezers. Their collective effort, detailed in their publication in the iScience journal, introduces a groundbreaking method using multiplexed vortex beams, marking a significant leap forward in photonics and practical applications.

The researchers embarked on this journey by ingeniously designing a multiplexed spiral phase mask (MSPM). This diffractive optical element is key to their method, creating multiple concentric vortex beams, each with its unique topological charge. This intricate setup enables the simultaneous control of multiple microparticles, each following distinct paths. Francisco Muñoz-Pérez, a leading scientist in the study, explains, “The MSPM transforms the landscape of optical tweezers, bringing an unprecedented level of control and versatility in manipulating particles at the microscale.”

Exploring the core findings of their research, the team discovered that these vortex beams could transfer angular momentum to trapped microparticles. This results in the particles independently orbiting the optical axis within each vortex. Dr. Vicente Ferrando sheds light on this phenomenon: “It’s a mesmerizing interplay of light and matter. The vortex beams endow the particles with a kind of rotational motion, showcasing a fascinating aspect of physics.”

The study’s discoveries extend far beyond theoretical physics. They open doors to myriad practical applications, particularly in areas where fine control at the micro and nanoscale is crucial, such as in micro-robotics and biological sciences. Francisco Muñoz-Pérez emphasizes, “Our work isn’t just about understanding interactions between light and matter. It’s about harnessing these interactions for real-world applications, where precision is crucial.”

In challenging conventional norms of optical trapping, the research demonstrated stable trapping of particles without the need for amplitude modulation. This insight, as Francisco Muñoz-Pérez highlights, revolutionizes our understanding of how light interacts with microscopic particles.

In conclusion, the research led by Francisco Muñoz-Pérez and his team represents a pivotal moment in optical manipulation. Their work merges the fields of photonics and material science, enriching our understanding of light-matter interaction and laying the groundwork for future technological innovations. The implications of their findings are significant, potentially transforming numerous scientific and industrial fields.

Journal Reference

Muñoz-Pérez, F. M., Ferrando, V., Furlan, W. D., Castro-Palacio, J. C., Arias-Gonzalez, J. R., & Monsoriu, J. A. (2023). “Multiplexed vortex beam-based optical tweezers generated with spiral phase mask.” iScience, 26(107987). DOI: https://doi.org/10.1016/j.isci.2023.107987.