{"created":"2023-06-19T10:29:53.695703+00:00","id":9965,"links":{},"metadata":{"_buckets":{"deposit":"2ca30205-1a64-4cae-9b9d-38357c9acedd"},"_deposit":{"created_by":18,"id":"9965","owners":[18],"pid":{"revision_id":0,"type":"depid","value":"9965"},"status":"published"},"_oai":{"id":"oai:muroran-it.repo.nii.ac.jp:00009965","sets":["216:487","41:227"]},"author_link":["58685"],"item_81_date_granted_17":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2019-03-25"}]},"item_81_degree_grantor_10":{"attribute_name":"学位授与機関","attribute_value_mlt":[{"subitem_degreegrantor":[{"subitem_degreegrantor_language":"ja","subitem_degreegrantor_name":"室蘭工業大学"},{"subitem_degreegrantor_language":"en","subitem_degreegrantor_name":"Muroran Institute of Technology"}],"subitem_degreegrantor_identifier":[{"subitem_degreegrantor_identifier_name":"10103","subitem_degreegrantor_identifier_scheme":"kakenhi"}]}]},"item_81_degree_name_11":{"attribute_name":"学位名","attribute_value_mlt":[{"subitem_degreename":"博士（工学）","subitem_degreename_language":"ja"}]},"item_81_description_25":{"attribute_name":"フォーマット","attribute_value_mlt":[{"subitem_description":"application/pdf","subitem_description_type":"Other"}]},"item_81_description_7":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"近年、インターネットの総通信量が増加傾向にあり、光通信システムのさらなる高速・大容量化を達成するため、光通信システムの最も基本的な要素である光導波路デバイスの極限までの小型化、低損失化が要求されている。従来、様々な光導波路デバイスは、設計者の電磁気現象に関する深い理解や、これまでに提案されてきた動作原理の知識等に基づいて設計が行われてきた。計算機の計算処理能力の向上や電磁界シミュレーション技術の発展によって、近年は光導波路デバイスの設計に数値シミュレーションを活用した構造最適化手法が積極的に利用されており、その中で、特にトポロジー最適化は非常に高い設計自由度持ち、デバイスの大幅な性能改善および新たな動作原理を持つデバイスの創生の可能性があるとして注目を集めている。従来の光導波路デバイスの感度解析に基づく構造最適化において、数値解析手法として有限要素法（ＦＥＭ）や時間領域有限差分法（ＦＤＴＤ法）等が利用されてきた。光導波路解析において、平面光波回路（ＰＬＣ）デバイス等、波長に対して長手方向のデバイス長が非常に長い場合に対しては、ビーム伝搬法（ＢＰＭ）が効率的な数値解析手法として幅広く利用されている。ＢＰＭを解析手法として用いた感度解析に基づく形状最適設計あるいはトポロジー最適設計例はこれまで報告されておらず、この最適化法が実現できれば感度解析に基づく構造最適化の計算コストが低減可能となり、ＦＥＭやＦＤＴＤ法等では計算コスト上困難な設計問題への応用が期待できる。本論文では、ＢＰＭを活用した光導波路素子の感度解析に基づくトポロジー最適化法の実現を新たに行っており、具体的に２次元ＢＰＭ、３次元セミベクトルＢＰＭ、３次元フルベクトルＢＰＭ、２次元時間領域ＢＰＭを光波伝搬解析手法として利用した場合のトポロジー最適化手法を実現している。本論文では特に、ＢＰＭとして横方向の離散化方法に有限差分法を用いるＦＤ?ＢＰＭ、材料分布の表現手法として密度法、感度解析手法として随伴変数法を適用する場合の感度計算方法を述べている。また、設計変数空間の探索手法には最速降下法を適用している。本手法を曲がり導波路の２次元近似設計問題および３次元設計問題へと適用し、いずれの問題においても提案するトポロジー最適設計手法によって特性が改善するように最適化計算が進むことを確認している。また、パワー分岐導波路、モード次数変換素子、導波路型反射器、偏波回転素子の設計を通して、提案するトポロジー最適化法の汎用性を明らかにしており、本設計アプローチが今後も発展が予想される石英系平面光波回路素子だけではなく、シリコンフォトニックデバイスのさらなる小型化・低損失化に貢献できる可能性を見出した。","subitem_description_language":"ja","subitem_description_type":"Abstract"},{"subitem_description":"In recent years, more compact and higher performance optical waveguide devices, which is a fundamental component in optical communication networks, are required in order to deal with the rapid increasing of internet traffic. The optical waveguide devices have been developed based on designer’s experience and profound understanding of guided-wave optics so far. Recently, the structural optimization based on numerical simulation has been used in the design of optical waveguide devices owing to the recent development of computer technology and simulation techniques. Topology optimization has possibility that the device performance is largely improved and a novel operation principle is discovered, because this optimal design method has particular high design of freedom among structural optimization methods. In conventional topology optimization, a finite element method (FEM), or a finite difference time domain (FDTD) method, etc. is utilized as a numerical simulation method of guided-wave in optical waveguides. A beam propagation method (BPM) has been widely used in the field of guided-wave optics, and it can efficiently analyze a long-length device which is difficult to address using the FEM or the FDTD, such as a planner light-wave circuit (PLC) device. It can be expected that the performance of such devices is highly enhanced with very low computational cost if the gradient-based topology optimization utilizing the BPM is realized. In this paper, new topology optimal design approaches utilizing the BPM for optical waveguide devices are realized. In this research, use of the 2DFD-BPM, the semi-vectorial FD-BPM based on alternative direction implicit method (ADIM), the full-vectorial FD-BPM (FV-FD-BPM) based on ADIM, and the time domain FD-BPM based on ADIM is studied.   The density method as a representation method of the refractive index distribution in the design region, the adjoint variable method as a sensitivity analysis method are employed to the proposed design approaches, and how to calculate the sensitivity is described in the case of using these methods. In the design example, the steepest descent method is employed as a gradient-based optimization algorithm for finding the minimum point of the objective function. The figure of merit is improved with increasing iteration count in 2D and 3D design problems of the bending waveguide using the proposed design approach, thus the validity of the proposed design approaches is confirmed. Moreover, the usefulness is also considered by designing the optical power splitters, mode order converter, waveguide reflector, and polarization rotator. It is shown that there is possibility that the proposed design approaches enhance the figure of merit of not only PLC devices but also the optical components in silicon on insulator (SOI) platform which is expected to be next-generation optical devices.","subitem_description_language":"en","subitem_description_type":"Abstract"}]},"item_81_dissertation_number_13":{"attribute_name":"学位授与番号","attribute_value_mlt":[{"subitem_dissertationnumber":"甲第440号"}]},"item_81_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15118/00009913","subitem_identifier_reg_type":"JaLC"}]},"item_81_link_5":{"attribute_name":"室蘭工業大学研究者データベースへのリンク","attribute_value_mlt":[{"subitem_link_text":"井口 亜希人（IGUCHI Akito）","subitem_link_url":"http://rdsoran.muroran-it.ac.jp/html/200000200_ja.html"}]},"item_81_subject_9":{"attribute_name":"日本十進分類法","attribute_value_mlt":[{"subitem_subject":"547","subitem_subject_scheme":"NDC"}]},"item_81_text_12":{"attribute_name":"学位の種別","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"課程博士"}]},"item_81_text_14":{"attribute_name":"報告番号","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"甲第440号"}]},"item_81_text_15":{"attribute_name":"学位記番号","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"博甲第440号"}]},"item_81_text_16":{"attribute_name":"研究科・専攻","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"工学専攻・先端情報電子工学コース"}]},"item_81_version_type_24":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_970fb48d4fbd8a85","subitem_version_type":"VoR"}]},"item_access_right":{"attribute_name":"アクセス権","attribute_value_mlt":[{"subitem_access_right":"open access","subitem_access_right_uri":"http://purl.org/coar/access_right/c_abf2"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorAffiliations":[{"affiliationNameIdentifiers":[{}],"affiliationNames":[{},{}]}],"creatorNames":[{"creatorName":"IGUCHI, Akito","creatorNameLang":"en"},{"creatorName":"井口, 亜希人","creatorNameLang":"ja"},{"creatorName":"イグチ, アキト","creatorNameLang":"ja-Kana"}],"familyNames":[{},{},{}],"givenNames":[{},{},{}],"nameIdentifiers":[{},{}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2020-02-29"}],"displaytype":"detail","filename":"A440.pdf","filesize":[{"value":"10.2 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"A440","objectType":"fulltext","url":"https://muroran-it.repo.nii.ac.jp/record/9965/files/A440.pdf"},"version_id":"5e503640-7971-44cf-a194-cc4819438802"},{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2019-06-25"}],"displaytype":"detail","filename":"A440_summary.pdf","filesize":[{"value":"343.3 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"A440_summary","objectType":"abstract","url":"https://muroran-it.repo.nii.ac.jp/record/9965/files/A440_summary.pdf"},"version_id":"f777e374-eb57-4285-9102-8bd8302f70cb"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"doctoral thesis","resourceuri":"http://purl.org/coar/resource_type/c_db06"}]},"item_title":"ビーム伝搬法を活用した光導波路デバイスの構造最適設計","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"ビーム伝搬法を活用した光導波路デバイスの構造最適設計","subitem_title_language":"ja"},{"subitem_title":"Structural optimal design with beam propagation method for optical waveguide devices","subitem_title_language":"en"}]},"item_type_id":"81","owner":"18","path":["227","487"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2019-06-25"},"publish_date":"2019-06-25","publish_status":"0","recid":"9965","relation_version_is_last":true,"title":["ビーム伝搬法を活用した光導波路デバイスの構造最適設計"],"weko_creator_id":"18","weko_shared_id":-1},"updated":"2023-10-19T07:31:23.545856+00:00"}