Metafiber transforming arbitrarily structured light

Abstract

Structured light has proven useful for numerous photonic applications. However, the current use of structured light in optical fiber science and technology is severely limited by mode mixing or by the lack of optical elements that can be integrated onto fiber end-faces for wavefront engineering, and hence generation of structured light is still handled outside the fiber via bulky optics in free space. We report a metafiber platform capable of creating arbitrarily structured light on the hybrid-order Poincaré sphere. Polymeric metasurfaces, with unleashed height degree of freedom and a greatly expanded 3D meta-atom library, were 3D laser nanoprinted and interfaced with polarization-maintaining single-mode fibers. Multiple metasurfaces were interfaced on the fiber end-faces, transforming the fiber output into different structured-light fields, including cylindrical vector beams, circularly polarized vortex beams, and arbitrary vector field. Our work provides a paradigm for advancing optical fiber science and technology towards fiber-integrated light shaping, which may find important applications in fiber communications, fiber lasers and sensors, endoscopic imaging, fiber lithography, and lab-on-fiber technology.

Broadband Diffractive Neural Networks Enabling Classification of Visible Wavelengths

“…Alternatively, 3D nanofabrication methods may be used to realize multiple metasurface layers. [ 31–33 ] The period between meta‐atoms reduces the proximity effect from two‐photon polymerization, resulting in an improved resolution that would be critical for applications involving shorter visible wavelengths. The robustness of the model could further be improved by accounting for the misalignment of the input PSF from the center of the diffractive layer and the angle of the incoming beam.…”

3D laser-nanoprinted meta-optics: a breakthrough photonic platform for wavefront shaping and molecular sensing

“…Recently, we have developed a new approach to metasurface fabrication based on 3D direct laser writing with unleashed height degree of freedom. We showcased multiple 3D laser-nanoprinted metasurfaces for a range of photonic applications, including ultrahigh-bandwidth holography [1], metafibre-enabled optical trapping [2], highly sensitive molecular sensing [3], achromatic fibre-optic focusing and imaging [4], and structured light generation on metafibres [5]. The optical performance of our demonstrated 3D laser-nanoprinted metasurfaces surpass previous 2D metasurfaces fabricated from planar lithography.…”

Two-photon polymerization lithography for imaging optics

“…In this context, 3D-printed micro-optics with flexibly designed free-form refractive optical elements could largely facilitate high quality fiber imaging and aberration correction [66,69,70]. In addition, metafibers (interfacing metasurfaces with the end face of an optical fiber) have recently emerged as a new platform to arbitrarily transform the fiber outputs [188], which can largely enrich the fiber functionalities that cannot be realized from 3Dprinted refractive optical elements. For instance, metafibers have the capacity of manipulating the fiber output in multiple degrees of freedom of light, including not only the amplitude and phase, but also the polarization and dispersion of guided fiber modes [71,72,188].…”

“…In addition, metafibers (interfacing metasurfaces with the end face of an optical fiber) have recently emerged as a new platform to arbitrarily transform the fiber outputs [188], which can largely enrich the fiber functionalities that cannot be realized from 3Dprinted refractive optical elements. For instance, metafibers have the capacity of manipulating the fiber output in multiple degrees of freedom of light, including not only the amplitude and phase, but also the polarization and dispersion of guided fiber modes [71,72,188]. The great flexibility of 3D laser nanoprinting opens the possibility of interfacing 3D-printed freeform micro-optics with ultrathin metafibers.…”