Advancements in Non-Diffracting Light Fields and Metasurfaces

The diffraction of light is a natural phenomenon where waves spread out as they propagate, limiting the efficient transmission of energy and information. Scientists have been working towards suppressing diffraction effects to maintain the shape and direction of light beams. Breakthroughs such as Airy beams (ABs) and Bessel beams (BBs) have greatly advanced fundamental optics and applications.

Traditional devices for modulating non-diffracting light fields have been bulky and had limitations such as low resolution and difficulty encoding the phase profile. However, the development of metasurfaces has brought about significant changes. Using nanoscale antenna arrays, metasurfaces can achieve multidimensional control of light fields through their birefringence, enabling the miniaturization of optical devices.

Recent advancements in the field have led to the successful reconstruction of non-diffracting light fields along the propagation path. Circularly Airy beams (CABs) naturally transformed into Bessel beams (BBs) after propagating a distance. This research was made possible by a proposed mechanism of joint local-global phase control, allowing for modulation of the radial phase gradient and encoding of more complex optical fields.

The research team decomposed the 2D problem into integrating 1D phase functions and superposing 2D phase functions. This process, referred to as the “Transformers” of the optical domain, was illustrated using theoretical analysis and ray tracing techniques. After modulation of the metasurface, scattered light converged into clear Airy beams, which overlapped to form non-diffracting Bessel beams.

Technological Innovations

By leveraging triple birefringent nanoantennas, new techniques for structuring light fields were introduced, doubling the number of light field types to six. The high tolerance of the device to manufacturing defects was also demonstrated, showcasing the potential for advanced on-chip, nano-optical platforms and innovative manufacturing technologies.

This research represents a pivotal step in the use of non-diffracting light fields and enhancing the multifunctionality of metasurfaces. It lays a solid foundation for the advancement of advanced optical platforms and manufacturing technologies, driving optical device performance and functionality to new heights.

The advancements in non-diffracting light fields and metasurfaces have opened up new possibilities for the manipulation and control of light beams. This research not only contributes to the development of optical technology but also paves the way for future innovations in the field.