Ultrafast all-optical diffraction switching using semiconductor metasurfaces
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Center for Integrated Nanotechnologies (CINT)
- Friedrich Schiller Univ. Jena (Germany). Abbe Center of Photonics, Inst. of Applied Physics
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Center for Integrated Nanotechnologies (CINT)
- Friedrich Schiller Univ. Jena (Germany). Abbe Center of Photonics, Inst. of Applied Physics; Friedrich Schiller Univ. Jena (Germany). Abbe Center of Photonics, Inst. of Solid State Physics
Ultrafast all-optical switching using Mie resonant metasurfaces requires both on-demand tunability of the wavefront of the light and ultrafast time response. However, devising a switching mechanism that has a high contrast between its “on” and “off” states without compromising speed is challenging. Here, we report the design of a tunable Mie resonant metasurface that achieves this behavior. Our approach utilizes a diffractive array of semiconductor resonators that support both dipolar and quadrupolar Mie resonances. By balancing the strengths of the dipole and quadrupole resonances, we can suppress radiation into the first diffraction order, thus creating a clearly delineated “off”-state at the operating wavelength. Then, we use optical injection of free- carriers to spectrally shift the multipoles and rebalance the multipole strengths, thereby enabling radiation into the diffraction order—all on an ultrafast timescale. We demonstrate ultrafast off-to-on switching with Ion/Ioff ≈ 5 modulation of the diffracted intensity and ultrafast on-to-off switching with Ion/Ioff ≈ 9 modulation. Furthermore, both switches exhibit a fast τtr ≈ 2.7 ps relaxation time at 215 μJ cm-2 pump fluence. Further, we show that for higher fluences, the temporal response of the metasurface is governed by thermo-optic effects. This combination of multipole engineering with lattice diffraction opens design pathways for tunable metasurface-based integrated devices.
- Research Organization:
- Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division
- Grant/Contract Number:
- AC04-94AL85000; NA0003525
- OSTI ID:
- 1810381
- Report Number(s):
- SAND--2021-7462J; 697244
- Journal Information:
- Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 21 Vol. 118; ISSN 0003-6951
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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