Fabrication of Large Area, Ordered Nanoporous Structures on Various Substrates for Potential Electro-Optic Applications

Nanoporous structures have attracted great attention in electronics, sensor and storage devices, and photonics because of their large surface area, large volume to surface ratio, and potential for high-sensitivity sensor applications. Normally, electron or ion beam patterning can be used for nanopores fabrication by direct writing. However, direct writing is a rather expensive and time-consuming method due to its serial nature. Therefore, it may not translate to a preferred manufacturing process. In this research, a perfectly ordered large-area periodic pattern in an area of approximately 1 cm2 has been successfully fabricated on various substrates including glass, silicon, and polydimethylsiloxane, using a two-step process comprising visible light-based multibeam interference lithography and subsequent pattern transfer processes of reactive ion etching and nanomolding. Additionally, the multibeam interference lithography templated anodized aluminum oxide process has been described. Since the fabrication area in multibeam interference lithography can be extended by using a larger beam size, it is highly cost effective and manufacturable. Furthermore, although not described here, an electrodeposition process can be utilized as a pattern transfer process. This large-area perfectly ordered nanopore array will be very useful for high-density electronic memory and photonic bandgap and metamaterial applications.

Prism-Based Laser Interference Lithography System for Simple Multibeam Interference Lithography

Laser interference lithography is a powerful technique of subwavelength-scale patterning. However, this technique requires a complicated optical system, the precise control and complexity of which increases exponentially with increasing number of beams. In this study, a compact prism-based laser interference lithography system using optical fibers and a prism was proposed to simplify the technique. In this system, the beam splitter and mirrors in a typical laser interference lithography system were replaced by a designed prism, and the pattern could be easily changed by only changing the prism, without other modification, irrespective of the number of beams required. In addition, because the laser and the laser interference lithography system are connected by an optical fiber, the system can be moved easily and flexibly. The fabrication of various submicroscale line patterns, holes, and dot patterns with a 270–1400 nm pitch was achieved using the proposed laser interference lithography system.

Повышение эффективности полимерного нанокомпозита для формирования фотонных структур методом оптической записи

In this work, the conditions for optimizing an optical recording material based on photosensitive acrylate-urethane nanocomposites with silicon oxide nanoparticles, for efficient Bragg gratings recording by multibeam interference method is presented. It was shown that the choice of the most effective monomers and their concentrations in the nanocomposite which depends on their structure and polymerization rate, followed by determination of the optimal recording radiation intensity for the given composition, makes it possible to adjust the conditions for component diffusion and redistribution, and hence, the formation of regions with different refractive indices in the recording medium. These results can be useful for creating complex 2D and 3D photonic structures based on the targeted modification of photosensitive polymer nanocomposites with different properties (luminescent, nonlinear optical, etc.).