Fiber-tip Tri-foci Metalens

The concept of ‘lab-on-fiber’ has sparked an abundance of research interest in optical fiber-integrated nanophotonic devices due to their impressive capacity to modulate light at the nanoscale. This increasing demand for improved functional diversity has led to further exploration of multifunctional fiber-tip metasurface. In this study, we design and characterize an all-dielectric tri-foci metalens directly patterned on the end facet of a large-mode-area photonic crystal fiber (LMA-PCF). Polarization-insensitive center focusing and polarization-sensitive off-axis bi-focusing have been substantiated at the operation wavelength of 1310 nm. The demonstration will be further explored to develop a diverse range of applications, such as optical communication and biological chiral imaging. With its impressive capacity to modulate light at the nanoscale, lab-on-fiber technology has opened up exciting new opportunities for research and development.