Tunable ultraviolet polarized light switch based on all-dielectric metasurfaces on a stretchable substrate

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Current ultraviolet (UV) passive optics are limited by poor tunability and lack of external modulation.
• Wide-bandgap semiconductor materials exhibit limited tunability in UV working media, hindering optical device development.

Purpose of the Study:

• To investigate the excitation of magnetic dipole resonances in the solar-blind UV region using hafnium oxide metasurfaces.
• To demonstrate a tunable optical switch in the solar-blind UV range modulated by mechanical strain.

Main Methods:

• Fabrication of hafnium oxide metasurfaces on an elastic polydimethylsiloxane (PDMS) substrate.
• Utilizing mechanical strain on the PDMS substrate to modulate near-field interactions between dielectric elements.
• Characterizing the optical response in the solar-blind UV wavelength range.

Main Results:

• Successfully excited magnetic dipole resonances in the solar-blind UV region.
• Demonstrated tunable optical switching by flattening the resonant peak with mechanical strain.
• Achieved modulation of light in the solar-blind UV range, effectively turning the optical switch on or off.

Conclusions:

• The hafnium oxide metasurface device offers a facile design for tunable UV optics.
• The mechanical strain modulation provides an external control method for UV optical switches.
• Potential applications include UV polarization modulation, optical communications, and spectroscopy.