Astrileux and Synopsys demonstrate the performance of new multilayer mask blank materials on photoresists and wafers in next generation lithography. We present new mask materials that exhibit superior on-wafer imaging properties, and improved performance in critical lithography parameters such as dose, Critical Dimensions (CD), Normalized Image Log Slop (NILS) and Depth of Focus (DOF). Specifically, we examine the optimization of material and architecture properties of coatings and demonstrate how their reflectivity profiles influence the CDs obtained for different pitches, illumination conditions and complex numerical aperture systems. Consequently, we can quantify direct improvements in CD as a result of new mask materials and their architectures.
Metalenses are flat lenses made from thin films with sub-wavelength nano-optical structures that can be created using the same processes that have been developed for integrated circuit manufacturing. We present a workflow that simulates the manufacturing process and enables process engineers and optical designers to study the impact of manufacturing on metalens performance without waiting for multiple manufacture-and-test cycles. To demonstrate this workflow, we design several metalenses and characterize the impact of process variation on absolute focusing efficiency, transmission, and output electric field.
Low-cost and high-precision fabrication of surface relief gratings on AR/VR waveguide combiners is one of the critical steps in realizing devices suitable for mass adoption. Displacement Talbot Lithography (DTL) has emerged as a viable technology that relies on the proven optical lithography approach of the semiconductor industry while offering a low-cost solution for large area printing of periodic structures of the kind required on waveguides. However, patterning with DTL differs from the common projection photolithography approaches in terms of the optical concepts used in printing an image in a photoresist layer. A key capability required for mass adoption is accurate simulation support for faster integration, process optimization, and mask design. Electronic Design Automation (EDA) tools are common for projection approaches and can now be used to understand DTL interactions with waveguide designs. This approach relies on three specific Synopsys modeling tools, namely S-Litho and RSoft Photonic Device Tools in conjunction with LightTools which are used for optimization of the photolithographic printing process (DTL) and the optical performance of the printed device (waveguide), respectively. A dedicated suite for modelling the DTL process within the S-Litho software was developed for this purpose. The model is calibrated and optimized using actual printing results in photoresist layers obtained through the DTL process. In this presentation we will show results of this new method that combines the optimization of DTL lithographic printing and optical performance of the resulting waveguide. The combination of the unique DTL solution and the comprehensive simulation capabilities holds great promise for accelerating the development and commercialization of AR devices.
Metalenses are flat devices that focus and manipulate optical waves. Unlike reflective and refractive optics, metalenses rely on phase shifts introduced by subwavelength metastructures. Demonstrate the cost and performance impact of using manufactured metaatoms from two lithography processes to design and manufacture metalenses. Design two types of metalenses, the first type (ideal) uses an ideal design made up of square metaatoms. This lens design is then simulated using both 193nm and 248nm lithography processes. The second type (manufacture-aware) uses a design that is built around metaatom profiles produced by the corresponding lithography process (193nm and 248nm respectively). By comparing the performance of these two approaches (ideal and manufacture-aware) we demonstrate the process performance impact can be reduced. Comparing 193nm and 248nm processes show a up to a 27% difference in monochromatic metalens performance for a design derived from ideal metaatoms. However, by simulating manufactured metaatoms and using them in the design stage, manufactured metalens performance returns to within 7% of ideal. When designing with manufactured metaatoms rather than ideal metaatoms, metalens performance is similar between both 193nm and 248nm processes and manufacture-aware design makes either process viable for visible-light metalens manufacturing.
Displacement Talbot Lithography (DTL) has emerged as a viable technology that relies on the proven photolithography approach of the semiconductor industry while offering a specific, low-cost solution for large area printing of periodic structures of the kind required on waveguides. Electronic Design Automation (EDA) tools are necessary for standard projection lithography approaches, and now can be used to understand DTL interactions with waveguide designs. Here, we present the first results from the development of a complete design and optimization approach that facilitates fabrication of waveguide devices with optimum processing conditions and targeted device performance.
Displacement Talbot Lithography (DTL) is an emerging photolithography technique for printing high-resolution periodic patterns. The image recorded through the DTL process differs from those created in projection printing or contact/proximity techniques, not only because it uses all longitudinal axis image planes, but also in the way the object (mask) transmission function is transformed into the recorded image. We present the main parameters involved in modeling the DTL patterning process and give examples relevant to applications such as AR/VR waveguide production. We also compare DTL to simulated projection lithography implementations. Like the well-known projection lithography case, the ability to accurately model and predict printing results is essential to exploring the process limits and possibilities with this new exposure technique.
Slow and stopped light systems form an important piece of the photonics puzzle by acting as memory devices. When used with few-photon light levels, these devices are fundamental to applications in quantum information science, quantum computing, and quantum communication. We report on our progress implementing a technique 1 for measuring the quantum state of light that has been stored in a warm-vapor slow-light system. This technique does not require careful mode matching can in fact be used to optimize the measured eld mode without a prior knowledge of the stored light.
Quantum information can be transferred from a beam of light to a cloud of atoms and controllably released at a later time. This process forms the basis of many important quantum memory devices that are fundamental to the future of quantum information science, quantum computing, and quantum communication. Prior experiments have stored light in a variety of systems, including cold atom clouds, warm atomic vapor, solid state materials, and optical fibers. To extend these successful investigations, the goal of our research program is to carry out a full characterization of the quantum states of stored-and-retrieved multimode light.
Photonic circuits require elements that can control optical signals with other optical signals. Ultra-low-light-level operation of all-optical switches opens the possibility of photonic devices that operate in the single-quantum regime, a prerequisite for quantum-photonic devices. We describe a new type of all-optical switch that exploits the extreme sensitivity to small perturbations displayed by instability-generated dissipative optical patterns. Such patterns, when controlled by applied perturbations, enable control of microwatt-power-level output beams by an input beam that is over 600 times weaker. In comparison, essentially all experimental realizations of light-by-light switching have been limited to controlling weak beams with beams of either comparable or higher power, thus limiting their implementation in cascaded switching networks or computation machines. Furthermore, current research suggests that the energy density required to actuate an all-optical switch is of the order of one photon per optical cross section. Our measured switching energy density of ~4.4 × 10-2 photons per cross section suggests that our device can operate at the single-photon level with modest system improvement.
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