Tidy3D FDTD by Flexcompute

⭐ Inverse Design of the Week ⭐  💎 GaP Photon Extractor for NV Centers in Diamond Enhancing photon collection efficiency from color centers is essential for advancing solid-state qubit systems in quantum information and metrology applications. High refractive index materials like diamond face total internal reflection, limiting photon extraction from embedded qubits. This week, we delve into the inverse design of a Gallium Phosphide (GaP) photon extractor that significantly improves photon collection efficiency. Using Tidy3D's inverse design, we optimized a compact 1.5 μm x 1.5 μm design region atop a diamond substrate, following the novel work from Prof. Kai-Mei Fu group and collaborators (https://lnkd.in/grwBsiEP). The design maximizes the minimum upward flux across three dipole source orientations (‘x’, ‘y’, and ‘z’), achieving:   • >10x enhancement for in-plane dipole orientations.   • >200x enhancement for out-of-plane dipoles compared to the no-extractor baseline. Fabrication constraints were incorporated through a smoothing and projection method, ensuring compliance with electron beam lithography’s 50 nm feature size requirements. The optimization process culminated in a design robust to binarization. Explore the details of our design workflow, from defining dielectric structures and running baseline simulations to achieving optimal flux enhancement and fabrication readiness. 💡 Check out our Python notebook for step-by-step insights here: https://lnkd.in/guFQ9Ntm #Photonics #InverseDesign #QuantumTechnology #Tidy3D #Flexcompute

🌟 Inverse Design of the Week 🌟 Inverse Design Optimization of a Plasmonic Nanoantenna Metasurface Plasmonic resonances in nanoantennas enable unique ways of controlling light, with numerous applications across the photonics industry. As we’ve showcased in previous weeks, topology optimization is a powerful tool for quickly designing and optimizing such structures. However, performing topology optimization on dispersive materials like metals can be challenging, and the implementation is often not straightforward. Fortunately, Tidy3D's powerful autograd integration greatly simplifies this process. This week, we leverage Tidy3D’s speed and robustness to perform gradient-based topology optimization targeting field enhancement at a specific location. In just 20 optimization steps (40 FDTD simulations), we achieved a field enhancement of up to 680 times while respecting fabrication constraints. Curious to see how this was achieved? Dive into the example here: https://lnkd.in/gQgVjkGV. For more examples of inverse design applied to metasurfaces and other structures, check out our application gallery: https://lnkd.in/g3hvjVi2. #Photonics #Plasmonics #Nanoantennas #InverseDesign #FieldEnhancement #Tidy3D #Flexcompute

🍁 𝗛𝗮𝗽𝗽𝘆 𝗧𝗵𝗮𝗻𝗸𝘀𝗴𝗶𝘃𝗶𝗻𝗴! 🍁 💡 𝗞𝗻𝗼𝘄 𝗙𝗹𝗲𝘅𝗰𝗼𝗺𝗽𝘂𝘁𝗲 𝗘𝗹𝗲𝗰𝘁𝗿𝗼𝗺𝗮𝗴𝗻𝗲𝘁𝗶𝗰 𝗦𝗶𝗺𝘂𝗹𝗮𝘁𝗶𝗼𝗻 𝗦𝗼𝗹𝘂𝘁𝗶𝗼𝗻 💡 As we gather around to celebrate this season of gratitude, we want to take a moment to thank you for choosing us on your photonics journey. As we look ahead, we’re more committed than ever to driving innovation, building connections, and delivering exceptional solutions for the engineering and scientific community. Our EM team is continuously committed to advancing simulation technology, from GPU-accelerated 𝗙𝗗𝗧𝗗, 𝗠𝗼𝗱𝗲, 𝗘𝗠𝗘, and 𝗛𝗲𝗮𝘁 solvers to exciting new developments—𝗣𝗵𝗼𝘁𝗼𝗻𝗙𝗼𝗿𝗴𝗲. RF and charge solvers are on the horizon. From all of us at Flexcompute, we wish you and your loved ones a wonderful Thanksgiving filled with joy, laughter, and plenty of pie! 🍁 #Thanksgiving #Gratitude #Photonics #Tidy3D #Flexcompute

A constant challenge we face is to ensure the fabricated PIC chips work just as how we design/simulate them. Explore how to use Tidy3D and PreFab to predict real fabrication variability and its impact on device performance!

Exciting news! 📣 We are thrilled to share that two members of Flexcompute, Zongfu Yu and Shanhui Fan are named as 𝗛𝗶𝗴𝗵𝗹𝘆 𝗖𝗶𝘁𝗲𝗱 𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵𝗲𝗿𝘀 𝗼𝗳 𝟮𝟬𝟮𝟰 for their groundbreaking contributions to physics and computational science. This honor underscores their impact in advancing scientific research and innovation. We’re proud to have such visionary leaders driving Flexcompute’s mission forward! 👉 Learn more about the Highly Cited Researchers 2024: https://lnkd.in/gbsKXfdp

🌟 𝗜𝗻𝘃𝗲𝗿𝘀𝗲 𝗗𝗲𝘀𝗶𝗴𝗻 𝗼𝗳 𝘁𝗵𝗲 𝗪𝗲𝗲𝗸 🌟 𝗧𝗼𝗽𝗼𝗹𝗼𝗴𝘆 𝗢𝗽𝘁𝗶𝗺𝗶𝘇𝗮𝘁𝗶𝗼𝗻 𝗼𝗳 𝗮 𝗪𝗮𝘃𝗲𝗴𝘂𝗶𝗱𝗲 𝗕𝗲𝗻𝗱 Waveguide bends play a crucial role in directing light within photonic integrated circuits. However, compact bends often introduce losses that can hinder circuit performance. In a previous post, we explored shape optimization for waveguide bends. This time, we focus on topology optimization to achieve compact, low-loss waveguide bend designs. By optimizing a pixelated design region and applying a conic filter to smooth the permittivity at each iteration, followed by tanh projection for binarization, our approach converges quickly. In just 25 iterations (or 50 FDTD simulations), we generate a 3x3 micron, 90-degree waveguide bend with significantly reduced loss compared to traditional circular or Euler bends. 🔍 Want to see how it’s done? Check out this detailed example notebook: https://lnkd.in/gagArYdm. 💡Exciting news: inverse design is now available directly in the Tidy3D web GUI, making the process seamless and accessible, even for those without coding experience. Try out the waveguide bend example on the GUI: https://lnkd.in/gJiSZA2d! #InverseDesign #IntegratedPhotonics #Innovation #Tidy3D #Flexcompute

Photonic Inverse Design for Everyone.

📣 𝗘𝘅𝗰𝗶𝘁𝗶𝗻𝗴 𝗻𝗲𝘄𝘀 𝗳𝗼𝗿 𝗼𝗽𝘁𝗶𝗰𝘀 𝗮𝗻𝗱 𝗽𝗵𝗼𝘁𝗼𝗻𝗶𝗰𝘀 𝗿𝗲𝘀𝗲𝗮𝗿𝗰𝗵! 📣 ⚡ 𝗧𝗵𝗲 𝗶𝗻𝘃𝗲𝘀𝘁𝗺𝗲𝗻𝘁 𝗶𝗻 𝗔𝗜 𝗵𝗮𝗿𝗱𝘄𝗮𝗿𝗲 𝗶𝘀 𝗮𝗰𝗰𝗲𝗹𝗲𝗿𝗮𝘁𝗶𝗻𝗴 𝗯𝗿𝗲𝗮𝗸𝘁𝗵𝗿𝗼𝘂𝗴𝗵𝘀 𝗶𝗻 𝗽𝗵𝗼𝘁𝗼𝗻𝗶𝗰𝘀 𝗿𝗲𝘀𝗲𝗮𝗿𝗰𝗵 Prof. Zongfu Yu, the Grainger Professor from the University of Wisconsin-Madison and co-founder of Flexcompute, along with collaborators from Stanford University, Flexcompute, and NVIDIA, has revealed how GPUs are dramatically speeding up complex simulations. With faster design iterations—up to 100x quicker—this cutting-edge tech opens doors for innovation in photonics, making research more efficient than ever. Learn more about this groundbreaking work: https://lnkd.in/gfPUfMGF

🌟 𝗜𝗻𝘃𝗲𝗿𝘀𝗲 𝗗𝗲𝘀𝗶𝗴𝗻 𝗼𝗳 𝘁𝗵𝗲 𝗪𝗲𝗲𝗸 🌟 🚀 𝗧𝗼𝗽𝗼𝗹𝗼𝗴𝘆 𝗢𝗽𝘁𝗶𝗺𝗶𝘇𝗮𝘁𝗶𝗼𝗻 𝗼𝗳 𝗮 𝗖𝗼𝗺𝗽𝗮𝗰𝘁 𝗚𝗿𝗮𝘁𝗶𝗻𝗴 𝗖𝗼𝘂𝗽𝗹𝗲𝗿 Grating couplers are essential in integrated photonics, bridging the gap between optical fibers and on-chip waveguides. However, traditional designs often face limitations when balancing high coupling efficiency, compactness, and wide bandwidth. So, how can we overcome these challenges? 💡 The answer lies in inverse design! This week, we're showcasing how topology optimization can be applied to develop a high-performance, compact grating coupler. Starting with a pixelated rectangular design region and an initial random refractive index distribution, we employ powerful inverse design techniques. Using the adjoint method, we compute the gradient of an objective function - focused on maximizing coupling efficiency while considering fabrication constraints. Over 𝟳𝟱 𝗶𝘁𝗲𝗿𝗮𝘁𝗶𝗼𝗻𝘀 (equivalent to 150 FDTD simulations), the refractive index distribution is adjusted to achieve a final design with a coupling efficiency of <𝟭.𝟱 𝗱𝗕, all while adhering to fabrication limits. Want to see the optimization process in action? 🔎  Dive into our interactive Python notebook that walks you through the inverse design journey step by step: https://lnkd.in/ghvH-9_9 #InverseDesign #IntegratedPhotonics #Innovation #Tidy3D #Flexcompute

🌟 𝗜𝗻𝘃𝗲𝗿𝘀𝗲 𝗗𝗲𝘀𝗶𝗴𝗻 𝗼𝗳 𝘁𝗵𝗲 𝗪𝗲𝗲𝗸 🌟 𝗦𝗵𝗮𝗽𝗲 𝗢𝗽𝘁𝗶𝗺𝗶𝘇𝗮𝘁𝗶𝗼𝗻 𝗼𝗳 𝗮 𝗖𝗼𝗺𝗽𝗮𝗰𝘁 𝗪𝗮𝘃𝗲𝗴𝘂𝗶𝗱𝗲 𝗧𝗮𝗽𝗲𝗿 Waveguide tapers are essential components in integrated photonics, facilitating the smooth transition between waveguides of different widths. Traditionally, minimizing insertion loss requires very long taper lengths - often hundreds of microns, especially in low-contrast material platforms. Besides linear tapers, designers often turn to parabolic or exponential taper shapes to achieve incremental performance gains, but these approaches don't significantly reduce the device footprint. 🙋𝗜𝘀 𝗶𝘁 𝗽𝗼𝘀𝘀𝗶𝗯𝗹𝗲 𝘁𝗼 𝗱𝗲𝘀𝗶𝗴𝗻 𝘂𝗹𝘁𝗿𝗮-𝗰𝗼𝗺𝗽𝗮𝗰𝘁, 𝗹𝗼𝘄-𝗹𝗼𝘀𝘀 𝘄𝗮𝘃𝗲𝗴𝘂𝗶𝗱𝗲 𝘁𝗮𝗽𝗲𝗿𝘀 𝘂𝘀𝗶𝗻𝗴 𝗶𝗻𝘃𝗲𝗿𝘀𝗲 𝗱𝗲𝘀𝗶𝗴𝗻? This week, we're spotlighting the shape optimization of a waveguide taper using the powerful inverse design method. Starting with a basic linear taper, we iteratively adjust its shape based on gradients computed via the adjoint method - all managed automatically by Tidy3D. Our approach also leverages a smoothness penalty term in the objective function to prevent sharp features that could complicate fabrication—a convenient built-in feature of Tidy3D's optimization toolbox. With this method, we reduce the loss while keeping the taper compact. High-performance, space-efficient designs like these will drive the future of integrated photonics! Are you curious to see how it's done? Dive into the Python notebook and start your journey into the inverse design here: https://lnkd.in/grfu9atT. #Photonics #InverseDesign #ShapeOptimization #Waveguide #Innovation #IntegratedPhotonics #Tidy3D