Authors: J-H Seo, J. Park, D. Zhao, H. Yang, W. Zhou, B-K Ju, Z. Ma
Affilation: University of Wisconsin-Madison, United States
Pages: 23 - 26
Keywords: broadband membrane reflectors, transfer printing
Large-area broadband reflectors based on photonic crystals can enable a number of optoelectronic and photonics devices. To create nano patterns, nanoimprinting, electron-beam lithography and focused ion beam patterning techniques are commonly used. However, these methods offer low speed, small patterning area and at high cost. Laser Interference Lithography (LIL), on the other hand, can be used to easily generate nano patterns with perfect ordering. LIL is maskless, fast and can generate large area nano pattern at low cost. In this study, two-dimensional photonic crystal slab structures were formed by the LIL technique on silicon-on-insulator (SOI) wafer. The buried oxide layer was selectively undercut and released top Si layer referred to as Si nanomembrane reflector. This membrane reflector was then picked up and printed by employing an elastic stamp transfer technique onto glass substrate. As high as 95% of reflection of the multiple points on the sample in the range of near IR, above 1200 nm of wavelength was observed from the reflector. We believe that we have demonstrated the simplest and easiest method to fabricate large-size surface-normal ultra-compact broadband reflectors. The devices to be enable by the LIL patterning techniques may have significant impact on future optoelectronic and photonic applications.