Large-size printed broadband membrane reflectors by laser interference lithography

Large-area broadband reflectors based on photonic crystals can enable a number of optoelectronic and photonics devices. To create nano-scale patterns, electron-beam lithography and focused ion beam patterning techniques are commonly used. However, these methods are very slow and hard to form very large area patterns. 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 patterning technique and reactive ion etching (RIE) process on silicon-on-insulator (SOI) wafer. Top patterned Si nanomembrane layer was then released from the SOI substrate by selectively etching away the buried oxide layer. This top Si membrane reflector (MR) was then picked up and printed onto glass substrate by employing an elastic stamp transfer printing technique.. High reflectivity broadband reflection reflectors on glass were obtained, with measured reflectivity of 92% around 1200 nm. Large area uniform patterns were verified experimentally with measured reflectivity from multiple measurement locations. The work can lead to high performance membrane reflector manufacturing based on very simple and cost-effective approach. The devices to be enable by the LIL patterning techniques shall have significant impact on future optoelectronic and photonic applications.