EurekAlert February 17, 2022
Using metasurfaces researchers in Norway designed a device in which a metasurface is suspended on a membrane ring made of a thin-film lead zirconate titanate (PZT) film, which allows the PZT to move the metasurface when a voltage is applied. To demonstrate how MEMS-metasurfaces could function as a varifocal lens doublet, they placed a second metasurface lens after the MEMS-metasurface. Varying the separation distance between the lenses through MEMS displacement allowed researchers to tune the focal point of the lens doublet on the fly. The researchers showed that applying 23 volts allowed the PZT membrane to move the metasurfaces 7.2 microns, producing a focal length change of around 250 microns. They note that this range can be further improved with metalenses that have a stronger focusing power and by optimizing the MEMS design for longer stroke actuation. Because it is extremely compact and lightweight, and tunable the new lens could be useful for portable medical diagnostic instruments, drone-based 3D mapping and other applications where miniaturization can open new possibilities…read more. Open Access TECHNICAL ARTICLE
Tuning the effective focal length of the metasurface lens doublet by MEMS actuation… Credit: Optics Letters Vol. 47, Issue 5, pp. 1049-1052 (2022)Â