D.J. McGee
The College of New Jersey,
United States
Keywords: photofabrication, lithography, maskless, diffractive, surface relief grating
Summary:
We have developed a new photofabrication technology for surface microstructures. It is a 2.5D laser-writing process known as digital polarization optical printing (DPOP). The DPOP process writes surface microstructures in real-time with no post-exposure chemical processing required. The print media is a polymeric film fabricated from commercially available components and the light source is a 100 mW blue (488 nm) laser. The print media exhibits a mechanical distortion in response to polarized optical illumination, enabling the controllable and reversible generation of microscale surface features that can be used immediately following exposure and/or subsequently replicated using nanoimprint lithography or hot imprint stamping. Because this process is driven by optical polarization, the requirements for environmental stability are considerably relaxed over intensity-based writing schemes, ultimately enabling this innovation to have a benchtop footprint. Currently this technology has a 600 nm resolution and can print surface relief features up to 1.0 micron in height, with surface coverage areas from 50 x 50 µm2 up to 50 x 50 mm2. Because this system employs off-the-shelf optical and electromechanical components, it is an accessible and affordable platform for printing novel optical surface microstructures with applications in optical document security, diffractive optical elements, and planar diffractive lenses, among others. It will also find applications in bioengineering where template surfaces for directed cell growth are needed as well as surface science, where there is a need for surfaces with light-tunable anisotropy.