[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-82761-en":3,"doc-seo-82761-105":30,"detail-sidebar-cat-0-en-105":91},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":20,"is_deleted":4,"is_public":21,"is_downloadable":21,"audit_status":21,"page_count":22,"language":23,"language_code":24,"site_id":25,"html_lang":24,"table_of_contents":26,"faqs":27,"seo_title":13,"seo_description":14,"update_tm":28,"read_time":29},82761,549758252649,"Ivy","https://ap-avatar.wpscdn.com/avatar/8000253669c5317157?_k=1778319167496531819",8,"Research & Report","OptiClear Differentiable Curvilinear Design Rule Legalization for Inverse Designed Photonic Devices","Photonic inverse design produces ultra-compact, high-performance devices with highly curvilinear, non-intuitive geometries, yet their masks often violate fabrication design rules and block foundry manufacturing. Existing legalization approaches for rectilinear Manhattan layouts do not transfer to curvilinear photonic boundaries. OptiClear introduces a curvilinear design rule legalization framework with two complementary engines: OptiClear-R for efficient rule-based iterative morphology-guided mask processing, and OptiClear-D for differentiable minimum-distortion optimization under morphological constraints. Evaluations show violations reduced from thousands to zero while preserving optical functionality.","OptiClear: Differentiable Curvilinear Design Rule Legalization for  \nInverse-Designed Photonic Devices  \nHongjian Zhou 1 , Haoyu Yang3 , Nicholas Gangi2 , Zhaoran (Rena) Huang2 , Jiaqi Gu 1,†  \n1Arizona State University 2Rensselaer Polytechnic Institute 3NVIDIA Corporation  \n†[jiaqigu@asu.edu](jiaqigu@asu.edu)  \narXiv :2607 .03632v1 [physics .optics] 3 Jul 2026  \nAbstract  \nPhotonic inverse design enables ultra-compact, high-performance devices with highly curvilinear and non-intuitive geometries, but the resulting layouts often violate fabrication design rules and hinder foundry manufacturing. Legalization methods designed for rectilinear Manhattan electrical layouts are not directly applicable to curvilinear inverse-designed photonic devices. Meanwhile, existing fabricationaware inverse-design methods apply soft penalties on small features and sharp curvatures, but still cannot guarantee design-rule-compliant final layouts. In this work, we present OptiClear, a curvilinear design rule legalization framework for inverse-designed photonic devices. OptiClear provides two complementary legalization engines: OptiClear-R, a rule-based morphological legalizer that efficiently resolves violation regions through iterative morphology-guided mask processing, and OptiClear-D, a differentiable legalizer that formulates legalization as a minimum-distortion mask optimization problem under morphological stationary-point constraints, explicitly seeking a rule-compliant layout with minimal geometric deviation from the original design. We further develop customized differentiable morphological GPU operators that significantly improve the scalability of high-resolution mask legalization. Comprehensive evaluation across diverse inverse-designed photonic devices and a wide range of designrule settings shows that OptiClear reduces design-rule violations from thousands to zero. The rule-based legalizer offers high runtime efficiency, while the differentiable legalizer more faithfully preserves the original optical functionality. This work establishes curvilinear design rule legalization as a practical post-design electronic-photonic design automation (EPDA) stage for translating high-performance inversedesigned photonic layouts into manufacturable tape-out-ready devices. The differentiable formulation also opens the door to future end-to-end design-rule-aware curvilinear inverse hardware design.  \n1 Introduction  \nPhotonic integrated circuits (PICs) are increasingly important for emerging applications such as optical interconnects, lidar, biosensing, quantum photonics, and optical computing, due to their advantagesin speed, bandwidth, and energy efficiency [1–6]. As PIC complexity continues to grow, there is increasing demand for compact and highperformance photonic devices with advanced application-specific functionality. In this context, photonic inverse design [7] has emerged as a powerful paradigm for device synthesis. By optimizing the material permittivity distribution over a much larger design space than conventional parameterized design, inverse design has enabled ultracompact photonic components with highly non-intuitive geometries and excellent optical performance on diverse applications.  \nHowever, the layouts produced by photonic inverse design are often extremely challenging to manufacture in foundry flows [8] . Unlike conventional hand-designed photonic devices with relatively regular geometry, inverse-designed devices typically exhibit highly curvilinear, non-Manhattan boundaries, dense subwavelength details, irregular notches, and narrow gaps. As a result, the final layouts frequently  \nviolate fabrication design rules, including minimum width, minimum spacing, area, curvature, and related curvilinear mask constraints. Anon-compliant layout may require a design-rule waiver (e.g., AIM Photonics), may be rejected by the foundry (e.g., GlobalFoundries, TSMC), and carry high risks of pattern distortion, yield loss, and degraded function","cbCail36PXC65SQN","https://ap.wps.com/l/cbCail36PXC65SQN","pdf",2782831,3,1,9,"English","en",105,"# Abstract\n# Introduction","[{\"question\":\"Why is design rule legalization difficult for inverse-designed photonic devices?\",\"answer\":\"Inverse-designed layouts often have highly curvilinear, non-Manhattan boundaries, dense subwavelength details, narrow gaps, and irregular notches. Width, spacing, curvature, and area constraints are tightly coupled, so fixing one violation can create others in a highly nonconvex, discrete process.\"},{\"question\":\"What are the two legalization engines proposed in OptiClear?\",\"answer\":\"OptiClear includes OptiClear-R, a rule-based morphological legalizer that resolves violation regions via iterative morphology-guided mask processing, and OptiClear-D, a differentiable legalizer that frames legalization as a minimum-distortion mask optimization problem under morphological stationary-point constraints.\"},{\"question\":\"What benefits does OptiClear demonstrate in reducing violations while preserving device performance?\",\"answer\":\"Across diverse inverse-designed photonic devices and varied design-rule settings, OptiClear reduces design-rule violations from thousands to zero. The rule-based engine emphasizes runtime efficiency, while the differentiable formulation more faithfully preserves the original optical functionality and enables future end-to-end rule-aware inverse hardware design.\"}]",1784182756,23,{"code":4,"msg":31,"data":32},"ok",{"site_id":25,"language":24,"slug":33,"title":13,"keywords":34,"description":14,"schema_data":35,"social_meta":86,"head_meta":88,"extra_data":90,"updated_unix":28},"opticlear-differentiable-curvilinear-design-rule-legalization-for-inverse-designed-photonic-devices","",{"@graph":36,"@context":85},[37,53,68],{"@type":38,"itemListElement":39},"BreadcrumbList",[40,44,48,50],{"item":41,"name":42,"@type":43,"position":21},"https://docshare.wps.com","Home","ListItem",{"item":45,"name":46,"@type":43,"position":47},"https://docshare.wps.com/document/","Document",2,{"item":49,"name":12,"@type":43,"position":20},"https://docshare.wps.com/document/research-report/",{"item":51,"name":13,"@type":43,"position":52},"https://docshare.wps.com/document/opticlear-differentiable-curvilinear-design-rule-legalization-for-inverse-designed-photonic-devices/82761/",4,{"url":51,"name":13,"@type":54,"author":55,"headline":13,"publisher":57,"fileFormat":60,"inLanguage":24,"description":14,"dateModified":61,"datePublished":62,"encodingFormat":60,"isAccessibleForFree":63,"interactionStatistic":64},"DigitalDocument",{"name":9,"@type":56},"Person",{"url":41,"name":58,"@type":59},"DocShare","Organization","application/pdf","2026-07-24","2026-07-16",true,{"@type":65,"interactionType":66,"userInteractionCount":20},"InteractionCounter",{"@type":67},"ViewAction",{"@type":69,"mainEntity":70},"FAQPage",[71,77,81],{"name":72,"@type":73,"acceptedAnswer":74},"Why is design rule legalization difficult for inverse-designed photonic devices?","Question",{"text":75,"@type":76},"Inverse-designed layouts often have highly curvilinear, non-Manhattan boundaries, dense subwavelength details, narrow gaps, and irregular notches. Width, spacing, curvature, and area constraints are tightly coupled, so fixing one violation can create others in a highly nonconvex, discrete process.","Answer",{"name":78,"@type":73,"acceptedAnswer":79},"What are the two legalization engines proposed in OptiClear?",{"text":80,"@type":76},"OptiClear includes OptiClear-R, a rule-based morphological legalizer that resolves violation regions via iterative morphology-guided mask processing, and OptiClear-D, a differentiable legalizer that frames legalization as a minimum-distortion mask optimization problem under morphological stationary-point constraints.",{"name":82,"@type":73,"acceptedAnswer":83},"What benefits does OptiClear demonstrate in reducing violations while preserving device performance?",{"text":84,"@type":76},"Across diverse inverse-designed photonic devices and varied design-rule settings, OptiClear reduces design-rule violations from thousands to zero. The rule-based engine emphasizes runtime efficiency, while the differentiable formulation more faithfully preserves the original optical functionality and enables future end-to-end rule-aware inverse hardware design.","https://schema.org",{"og:url":51,"og:type":87,"og:title":13,"og:site_name":58,"og:description":14},"article",{"robots":89,"canonical":51},"index,follow",{"doc_id":7,"site_id":25},{"code":4,"msg":5,"data":92},[93,97,101,105,110,115,120,123,127,130,134],{"id":21,"doc_module":4,"doc_module_name":46,"category_name":94,"show_sort_weight":95,"slug":96},"Story & Novel",90,"story-novel",{"id":47,"doc_module":4,"doc_module_name":46,"category_name":98,"show_sort_weight":99,"slug":100},"Literature",80,"literature",{"id":52,"doc_module":4,"doc_module_name":46,"category_name":102,"show_sort_weight":103,"slug":104},"Exam",70,"exam",{"id":106,"doc_module":4,"doc_module_name":46,"category_name":107,"show_sort_weight":108,"slug":109},5,"Comic",60,"comic",{"id":111,"doc_module":4,"doc_module_name":46,"category_name":112,"show_sort_weight":113,"slug":114},6,"Technology",50,"technology",{"id":116,"doc_module":4,"doc_module_name":46,"category_name":117,"show_sort_weight":118,"slug":119},7,"Healthcare",40,"healthcare",{"id":11,"doc_module":4,"doc_module_name":46,"category_name":12,"show_sort_weight":121,"slug":122},30,"research-report",{"id":22,"doc_module":4,"doc_module_name":46,"category_name":124,"show_sort_weight":125,"slug":126},"Religion & Spirituality",20,"religion-spirituality",{"id":125,"doc_module":4,"doc_module_name":46,"category_name":128,"show_sort_weight":125,"slug":129},"World Cup","world-cup",{"id":131,"doc_module":4,"doc_module_name":46,"category_name":132,"show_sort_weight":131,"slug":133},10,"Lifestyle","lifestyle",{"id":135,"doc_module":4,"doc_module_name":46,"category_name":136,"show_sort_weight":106,"slug":137},19,"General","general"]