Sol-gel zirconia diffraction grating using a soft imprinting process

A zirconia diffraction grating with high diffraction efficiency was fabricated using a soft imprinting technique and a sol-gel method. The imprinting process involved dropping zirconia nanoparticle dispersion onto a silicone (polydimethylsiloxane) mold, which was transferred from the patterned photoresist grating through the molding process. The first-order diffraction transmittance of the fabricated zirconia gel grating with a 1.0-μm pitch and a depth of 0.58 μm reached 29.4% at a wavelength of 632.8 nm (zeroth-order transmittance: 18.1%). This high aspect ratio grating can be fabricated in a simpler manner and at lower cost compared to conventional gratings.