Topology optimization and fabrication of photonic crystal structures October 22, 2020 Electron Beam Lithography, Photomask / Direct Write Lithography 0 Topology optimization is used to design a planar photonic crystal waveguide component resulting in significantly enhanced functionality. Exceptional transmission through a photonic crystal waveguide Z-bend is obtained using this inverse design strategy. The design has been realized in a silicon-on-insulator based photonic crystal waveguide. A large low loss bandwidth of more than 200 nm for the TE polarization is experimentally confirmed. For full details: Attached files often contain the full content of the item you are viewing. Be sure and view any attachments. resources_se/Optical-22.PDF 615.91 KB Related Articles Si-Based Photonic Crystals and Photonic-Bandgap Waveguides We studied various types of 2D and 3D Si-based photonic crystal structures that are promising for future photonic integrated circuit application. With regard to 2D SOI photonic crystal slabs, we confirmed the formation of a wide photonic bandgap at optical communication wavelengths, and used structural tuning to realize efficient single-mode line-defect waveguides operating within the bandgap. As regards 3D photonic crystals, we used a combination of lithography and the autocloning deposition method to realize complicated 3D structures. We used this strategy to fabricate 3D full-gap photonic crystals and 3D/2D hybrid photonic crystals. Drilled alternating-layer structure for three-dimensional photonic crystals with a full band gap A new three-dimensional photonic crystal structure is designed to simplify fabrication. A calculation of the band structure predicts that this photonic crystal has a complete photonic band gap in all directions. The entire three-dimensional periodic structure, except for the vertically drilled holes, is formed by automatic shaping during bias sputtering deposition. Fabrication of subwavelength, binary, antireflection surface-relief structures in the near infrared Subwavelength, binary surface-relief structures are artificial materials with an effective index of refraction that can be tailored by varying the duty cycle of the binary pattern. These structures have the significant advantage of requiring only a single lithography and etch step for fabrication. We demonstrate a specifically designed antireflection structure in a material system (GaAs) and at a wavelength (975 nm) directly integrable with GaAs-based vertical cavity surface-emitting lasers and which exhibits strong polarization-dependent properties. Fabrication is performed using electron beam lithography and reactive-ion-beam etching. The observed reflectivity is 2% for TE polarization and 23% for TM polarization, a difference in reflectivity of over a factor of 10 for the two polarizations. Confined Band Gap in an Air-Bridge Type of Two-Dimensional AlGaAs Photonic Crystal The transmittance spectrum for an air-bridge type of AlGaAs photonic crystal (PC) slabs successfully fabricated was measured. It is found that the observed spectrum is consistent with both the theoretical band structure and the calculated one. Moreover, the transmittance due to the modes below the light line is found to be almost 100%, indicating that the guided modes should exist. Fabrication of Nano-Structures using EB-Lithography and its Application to Long-Wavelength Quantum-Wire Lasers It is important to fabricate high density and high uniformity nano-structures for the realization of quantum wire lasers. In this work, 1.5µm-wavelength GaInAsP/InP quantum wire lasers were fabricated by electron beam (EB) lithography, and wet chemical etching followed by embedding organic metal vapor phase epitaxy (OMVPE) growth. Lithography for sub-60 nm resist nanostructures As the semiconductor community continues to follow the Semiconductor Industry Association Roadmap, resist structures are being printed further into the nanometer domain. However, a persistent issue for successful sub-60 nm resist patterning is mechanical stability at high aspect ratios. The objective of this article is to understand what processing conditions facilitate processing resist nanostructures with useful aspect ratios for the fabrication of sub-60 nm transistors. We have found that, in aqueous based development and rinse, if the resist thickness is reduced, then the aspect ratio is sacrificed for the sake of resolution. The implication is that there is a resolution limit at which resist structures will have aspect ratios that are useful for device fabrication. We have also found that there are development effects that occur in the thick film regime that are not reproducible with thin films. The best resolution structures we have been able to print are lines of 28 nm in width using direct write electron-beam lithography on negative chemically amplified resists NEB-22 and NEB-31 (Sumitomo Chemical Inc.) with an aspect ratio of about 3. To put this result in perspective, this is about 40 molecules wide. Showing 0 Comment Comments are closed.