Understanding the dynamic behavior of photopolymers in nanoscale environment is essential to improving MEMS/NEMS device fabrication technologies. Here, we unveil the highly nonlinear behaviors of photopolymers exhibited during the process of light-controlled, low-pressure nanoimprinting. Such peculiarities can complicate the relation between the UV-dose and the height of the nanoimprinted feature, degrading the accuracy of the height control. To address the issue, we establish a theoretical process model and used the control of the nanoimprinting height for structural coloring applications. Our findings will broadly benefit nanotechnology and nanoscience.
Recently, there have been notable advances in nanophotonic structural color generation which enabled various applications in display, anti-counterfeiting, sensors and detectors. However, most advances in this domain have been achieved through the use of high-index materials which require expensive and complex fabrication. In this work, we enable low-index polymer nanostructures to generate structural colors using the multipolar decomposition technique which allows a better understanding and design of the scattering process by identifying the dominant multipole modes from the scattered fields. We set a polymeric (n~1.56) cuboid as the structural color generation platform, examined the contributions of various multipoles from the wave scattered by it, and synthesized the desired color spectrum by adjusting only the height of the cuboid. To validate our findings, we fabricated the designed structural color pixels via light-controlled, low-pressure nanoimprinting and measured the color and spectrum from them. Our experimental results agreed well with the simulation results, providing insights for bringing further advances to structural coloring.
In recent years, there has been tremendous development in photonic integrated circuits (PICs) because of the growing demand for computational power and the slowing down of transistor shrinkage. PICs are seen as a promising technology for developing next-generation technologies including the Internet of Things, on-chip data routers, and optical quantum computers due to their compatibility with the long-established complementary metal-oxide-semiconductor fabrication technology and making use of common materials such as silicon and silicon dioxide. As the size of the PICs is shrinking and considering different aspects such as modal size mismatch, fabrication/packaging cost, it has become increasingly difficult to couple light efficiently in-plane or out-of-plane among different photonic elements such as waveguides and fibers. In this study, we propose a two-layer grating coupler using a horizontally placed angle-polished single-mode optical fiber. We used the finite-difference time-domain method and optimization tools including the inverse design technique to investigate the design parameters for performance enhancement of light coupling in silicon-on-insulator (SOI) integrated circuits. We achieved a coupling efficiency of -1.54 dB (70.15%) for fiber-to-SOI chip coupling and a coupling efficiency of -0.97 dB (80%) for chip-to-fiber coupling over a wide bandwidth.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.