JP3766811B2

JP3766811B2 - Optical waveguide unit manufacturing method and optical waveguide unit molding die

Info

Publication number: JP3766811B2
Application number: JP2002141519A
Authority: JP
Inventors: 光弘高崎; 誠飯田; 富也阿部; 光樹平野
Original assignee: Hitachi Cable Ltd; Hitachi Ltd
Current assignee: Hitachi Cable Ltd; Hitachi Ltd
Priority date: 2002-05-16
Filing date: 2002-05-16
Publication date: 2006-04-19
Anticipated expiration: 2022-05-16
Also published as: JP2003329868A

Description

【０００１】
【発明の属する技術分野】
本発明は、光ファイバなどに結合される光通信用の光導波路ユニットに関する。
【０００２】
【従来の技術】
従来、光ファイバに結合される光通信用の光導波路ユニット等の光部品には、光伝送損失と伝送帯域の点からガラス系無機材料が使用されている。しかし、最近では、加工性や価格の点で無機材料よりも有利なプラスチック系材料が光導波路用材料として注目され、種々のプラスチック材や製造方法の開発が行われている。例えば、特開平８−３１３７４７号公報や特開平９−１８９８１８号公報には、光導波路用材料としてプラスチック材を用い、露光技術を利用して製作する関連技術が記載されている。また、特開昭６３−１３９３０４号公報には、断面積の大きな光導波路を製造するための技術として、金型を使用する技術が記載されている。図９に、該公報記載の技術の概略を示す。同図（ａ）〜（ｅ）は光導波路ユニットの製造過程であって、（ａ）一部が突起状になった金型１を用意する、（ｂ）金型１の突起部１ａを転写してクラッド２'に溝を形成する、（ｃ）該溝にコア材を注入して固化し、コア３とする、（ｄ）クラッド面とコア面とを平坦にするようにクラッド２'の表面を研削加工する、（ｅ）加工面上に上クラッド４を接着する、を経て光導波路ユニットを製造する。
【０００３】
【発明が解決しようとする課題】
上記従来技術のうち、露光技術を用いるものでは、溝深さを数十ミクロン以上とする断面積の大きな光導波路の形成は精度が不十分となるおそれがある。また、特開昭６３−１３９３０４号公報記載のような金型を用いる技術では、金型１の突起部１ａを切削加工により形成するため、該突起部１ａの側面１ａ１（図１０）の面粗さ精度を確保できなかったり、該突起部１ａの側面１ａ２の根本部と金型平面との角１ａ２（図１０）に丸みが付いてしまいクラッド２'の溝の開口部のダレの原因となったりする。さらに、コア材の固化収縮分の補填を目的に、クラッド２'の溝内に液状のコア材を余剰に注入した場合には、クラッド２'とコア３とを平坦にするための研削加工などの後加工が必要（上記図９（ｄ））で、これを行うと、加工時において工具から与えられる力により、クラッド２'の溝側面とコア３との間に隙間が発生し易い。これら、突起部１ａの側面１ａ１などの不十分な面精度や、該突起部１ａの根本部の角の丸みによる溝開口部のダレや、クラッド２'の溝側面とコア３との間の隙間などはいずれも、光導波路ユニットにおける光伝送損失を増大させる要因となる。
本発明の課題点は、上記従来技術の状況に鑑み、光導波路ユニット技術において、コアやクラッドにプラスチック材を用いた場合にも、深さ数十ミクロン以上の光導波路断面を有する光導波路ユニットを、容易かつ安価に製作でき、光伝送損失の増大も抑えられるようにすることである。そのためには、クラッドの溝形成用の型の精度を簡易構成下で確保するとともに、コアの後加工を不要にすることが必要条件となる。
本発明の目的は、かかる課題点を解決できる技術の提供にある。
【０００４】
【課題を解決するための手段】
上記課題点を解決するために、本発明では、基本的には、光導波路ユニットのクラッド（第１の部材）製作用の成形型としては、板状部材の両面を複数の固定用部材（コマ）ではさみ該板状部材の一部が該固定用部材の端面から突出するようにした構成のものを用いる。クラッド（第１の部材）としては、該板状部材の突出部と該固定用部材の端面とをプラスチック材で覆い、該板状部材の突出部により該プラスチック材の表面に溝部を形成して硬化させた構成とする。さらに、第２の部材を該クラッド（第１の部材）に結合して上記溝部を覆った後、上記溝部内にコア材としての紫外線硬化樹脂等を注入し硬化させ、コア材を内蔵した光導波路ユニットの状態にする。具体的には、（１）光導波路ユニットとして、溝部（該当実施例：符号２Ｇ）を有しプラスチック材で構成された第１の部材（該当実施例：符号２）と、光透過性の材料から成り、上記第１の部材に結合されて上記溝部を覆う第２の部材（該当実施例：符号１４）と、上記溝部に設けられ上記第１の部材及び上記第２の部材よりも光の屈折率が高いプラスチック材で構成されたコア（該当実施例：符号３）と、を備えて成り、上記溝部のコア中を光信号が導かれるようにした構成とする。（２）上記（１）において、上記コアを、紫外線硬化樹脂で構成する。（３）上記（１）において、上記第１の部材を、上記溝部の側面の平均面粗さが１０×１０^-9ｍ以下である構成とする。（４）上記（１）において、上記第２の部材を、光の屈折率が上記第１の部材と略等しいプラスチック材で構成する。（５）光導波路ユニットの製造方法として、板状部材の両面を複数の固定用部材ではさみ、該板状部材の一部が該固定用部材の端面から突出する状態にする第１のステップ（該当実施例：符号Ｓ６０１）と、該板状部材の突出部と該固定用部材の端面とをプラスチック材で覆い、該板状部材の突出部により該プラスチック材の表面に溝部を形成して第１の部材を構成する第２のステップ（該当実施例：符号Ｓ６０２）と、該第１の部材を上記板状部材及び上記固定用部材から分離する第３のステップ（該当実施例：符号Ｓ６０３）と、第２の部材を上記第１の部材に結合し上記溝部を覆う第４のステップ（該当実施例：符号Ｓ６０４）と、上記溝部内に樹脂を注入し、硬化させてコアを構成する第５のステップ（該当実施例：符号Ｓ６０６）とを経て光導波路ユニットを製造する。（６）光導波路ユニットの製造方法として、板状部材の両面を複数の固定用部材ではさみ、該板状部材の一部が該固定用部材の端面から突出する状態にする第１のステップ（該当実施例：符号Ｓ６０１）と、該板状部材の突出部と該固定用部材の端面とをプラスチック材で覆い、該板状部材の突出部により該プラスチック材の表面に溝部を形成して第１の部材を構成する第２のステップ（該当実施例：符号Ｓ６０２）と、該第１の部材を上記板状部材及び上記固定用部材から分離する第３のステップ（該当実施例：符号Ｓ６０３）と、光透過性の材料から成る第２の部材を上記第１の部材に結合し上記溝部を覆う第４のステップ（該当実施例：符号Ｓ６０４）と、上記溝部内に紫外線硬化樹脂を注入し、該注入した紫外線硬化樹脂に紫外線を照射し該樹脂を硬化させ、上記第１の部材、第２の部材よりも光の屈折率が高いコアを構成する第５のステップ（該当実施例：符号Ｓ６０６）と、を経て光導波路ユニットを製造する。（７）上記（５）または（６）において、上記第１のステップでは、上記固定用部材の斜面部に外力を与えて上記板状部材を固定する。（８）上記（５）または（６）において、上記第２のステップでは、上記プラスチック材を加熱し軟化させた状態で上記板状部材の突出部と上記固定用部材の端面と覆って上記溝部を形成し、該形成後、該プラスチック材を冷却して硬化させる。（９）上記（５）または（６）において、上記第４のステップでは、上記第２の部材として光の屈折率が上記第１の部材と略等しいものを用いる。（１０）上記（６）において、上記第５のステップでは、上記紫外線を、上記第２の部材を介しかつ上記溝部の長手方向に対し相対移動させる状態で上記注入した紫外線硬化樹脂に照射する。（１１）光導波路ユニットを製造するための光導波路ユニット成形用型として、板状部材（該当実施例：符号５、２５、２６）と、該板状部材の両面をはさみ、端部を所定量突出させた状態で該板状部材を固定する複数の固定用部材（該当実施例：符号６、７、２７、２８、２９）とを備え、上記突出部で光導波路用溝部を形成可能にした構成とする。（１２）上記（１１）において、上記固定用部材を、それぞれが、上記板状部材に対向する面側に逃げ部（該当実施例：符号６'、７'、２７'、２８'、２８''、２９'）を有し、複数個の面で該板状部材に接触する構成とする。（１３）光導波路ユニットを備えた光通信機器として、該光導波路ユニットが、溝部を有しプラスチック材で構成された第１の部材と、光透過性の材料から成り上記第１の部材に結合されて上記溝部を覆う第２の部材と、上記溝部に設けられ上記第１の部材及び上記第２の部材よりも光の屈折率が高いプラスチック材で構成されたコアとを備えて成り、上記溝部のコア中を光信号が導かれるようにした構成とする。上記それぞれにおいて、上記板状部材、上記固定用部材は、それぞれ、端面を含め表面を予め高精度に加工されたものを用いる。
上記板状部材は、成形加工において、上記第１の部材の表面に上記溝部を形成する。上記第２の部材は、上記第１の部材に結合されることにより上記溝部を覆い上記コア材の注入される空間を形成するとともに、注入後のコアの研削等の後加工を不要にする。
【０００５】
【発明の実施の形態】
以下、本発明の実施例につき、図面を用いて説明する。
図１〜図６は、本発明の第１の実施例の説明図である。
本実施例は、１本の直線状の光導波路を有する光導波路ユニットの例である。図１は、第１の部材としてのクラッドを製作するための成形型の構成例、図２は、図１の成形型を用いてクラッドを製作するときの成形治具の構成例、図３は、図２の治具で製作されたクラッド、図４は、該製作したクラッドの溝部内に、液状など流動性を有するコア材を注入して硬化させてコアを形成する装置の構成例、図５は、図４の装置で製作された光導波路ユニットの断面、図６は、光導波路ユニットを製作する手順例を示すフロー図である。
図１において、５は板状部材、６、７は、板状部材５の両面をはさみ固定する固定用部材としてのコマ、６'はコマ６の板状部材接触面側に設けた逃げ部、７'はコマ７の板状部材接触面側に設けた逃げ部、８は、上記コマ７に斜面部３６を介して外力を与える押さえ部材、９は、上記コマ６に斜面部３５を介して外力を与える外枠部材である。板状部材５及びコマ６、７は、端面を含め表面を予め高精度に加工されている。コマ６、７の板状部材５への接触面は長手方向に直線状にされている。このため、板状部材５はコマ６、７によってはさまれて固定された状態においては、該コマ６、７の端面から所定の高さで突出した該板状部材５の突出部も長手方向に直線状となる。押さえ部材８は、図において下方に移動することで、斜面部３６を介しコマ７に外力を与える。外枠部材９は斜面部３５を介しコマ６に外力を与える。コマ６、７はそれぞれ、隙間のない状態で板状部材５の両面に接して該板状部材５を固定する。コマ７の逃げ部７'は、押さえ部材８から与えられる外力を該逃げ部７'の両側の接触面に分配しそれぞれの接触面での板状部材５との接触の面圧を高める。同様に、コマ６の逃げ部６'は、外枠部材９から与えられる外力を該逃げ部６'の両側の接触面に分配しそれぞれの接触面での板状部材５との接触の面圧を高める。逃げ部６'、７'は、板状部材のそり等も吸収する。
【０００６】
図２において、２ｐは、第１の部材としてのクラッドを形成するためのプラスチック材、１０は下側基材、１１は上側基材、１２は上側基材１１に設けた穴部、１３はねじである。他の部分は上記図１と同様である。成形治具としては、ねじ１３により、押さえ部材８を図の下方に移動させることで、コマ７に対し斜面部３６を介して外力を与え、板状部材５を、コマ６、７間に所定の位置及び姿勢で固定した状態とする。かかる状態の成形治具を加熱し、所定の温度に達したら、上側基材１１の穴部１２内にプラスチック材２ｐを入れ、熱により該プラスチック材２ｐを軟化させ、加圧して、板状部材５の突出部とコマ６、７の端面とを該プラスチック材２ｐが覆うようにし、次に、冷却して該プラスチック材２ｐを硬化させる。硬化後、該プラスチック材２ｐを成形治具から取出して第１の部材としてのクラッド２とする。
【０００７】
図３は、上記図２の成形治具により製作されたクラッド２の外観を示す。溝部２Ｇは板上部材５の突出部とコマ６、７の端面によって形成される。本実施例では、板上部材５の突出部及びコマ６、７の端面は予め高精度に加工されたものを組合わせてあるため、該溝部２Ｇは、溝寸法及び側面や底面の面粗さや平坦度等は所定の範囲内になっている。例えば、該溝部２Ｇの側面や底面の平均面粗さを１０×１０^-9ｍ以下とすると光伝送損失の増大を抑えられる。
【０００８】
図４は、上記製作したクラッド２の溝部２Ｇ内にコア材を注入し硬化させてコアを形成する装置の構成例である。本図４は、クラッド２が装着されたときの状態を示す。図４において、３'はコア材としての液状の紫外線硬化樹脂、１８は紫外線硬化樹脂３'を保持するシリンダ、１４は、クラッド２に結合され溝部２Ｇを覆う第２の部材としての光透過性のプラスチックシート材、１５は、該プラスチックシート材１４を押さえるためのガラス板、１６は、クラッド２が取付けられ、図の上下方向に移動するスライダ、１７は、該スライダ１６を支持する支持部材、２０は、紫外線硬化樹脂３'を硬化させるために照射される紫外線、２１は該紫外線２０の光源としてのランプ、２２、２３は遮蔽板、２４は、遮蔽板２２、２３間に形成されるスリット、１９は、溝部２Ｇ内に注入された液状の紫外線硬化樹脂を漏れないようにする漏れ止め部材、３ａ'は、溝部２Ｇ内に注入された紫外線硬化樹脂のうち硬化しない状態のもの、３ｂ'は硬化したものである。本実施例では、上記プラスチックシート材１４はクラッド２と同じ材質のものとする。また、紫外線硬化樹脂は、光の屈折率が上記クラッド２や上記プラスチックシート材１４よりも高いものを用いる。上記構成において、シリンダ１８に圧力を付加し、クラッド２の溝部２Ｇ内に紫外線硬化樹脂３’を重力方向に注入し、注入時に、または該注入の完了後に、溝部２Ｇ内の紫外線硬化樹脂に紫外線２０を、ガラス板１５及びプラスチックシート材１４を介して照射し、該紫外線硬化樹脂を硬化させる。このとき、紫外線２０は、スリット２４からクラッド２の溝部２Ｇに対し部分的に照射され、図の上から下へのスライダ１６の移動により、紫外線２０が、溝部２Ｇ内の紫外線硬化樹脂に対し、溝部２Ｇの下方にある部分から順次照射されるようにする。これによって、クラッド２の溝部２Ｇ内の紫外線硬化樹脂は下方側から順に硬化する。すなわち、未硬化の溝部の上端部にコア材料を補充することによって、溝部２Ｇの長手方向にコアが形成される。最終的に溝上端部に空隙が発生した場合にはその部分を切除してもよい。なお、スリット２４は、遮蔽板２２、２３の相互位置をずらすことにより、その大きさを変えられる。
【０００９】
図５は、図４の装置で製作された光導波路ユニットの外観図である。図５において、２は、溝部を有しプラスチック材で構成された第１の部材としてのクラッド、１４は、光透過性の材料から成り、上記クラッド２に結合されて上記溝部を覆う第２の部材としてのプラスチックシート材、３は、上記クラッド２の溝部に設けられ該クラッド２及び上記プラスチックシート材１４よりも光の屈折率が高い紫外線硬化樹脂で形成されたコアである。該コアは成形後の後加工は不要である。
【００１０】
図６は、上記図１〜図５で説明した光導波路ユニットの製作手順を示すフロー図である。
図６において、
（１）板状部材６の両面を複数の固定用部材としてのコマ６、７ではさみ、該板状部材５の一部が該コマ６、７の端面から突出する状態にする（ステップＳ６０１）。板上部材５及びコマ６、７は、予め高精度に加工されたものを用いる。（２）成形治具における加熱、加圧等により、上記板状部材５の突出部と該コマ６、７の端面とをプラスチック材で覆い、該板状部材５の突出部により該プラスチック材の表面に溝部２Ｇを形成して第１の部材としてのクラッド２を構成する（ステップＳ６０２）。
（３）上記クラッド２を上記板状部材５及び上記コマ６、７から分離する（ステップＳ６０３）。
（４）光透過性の材料から成る第２の部材としてのプラスチックシート材１４を上記第１の部材としてのクラッド２に結合し上記溝部２Ｇを覆う（ステップＳ６０４）。
（５）クラッド２にプラスチックシート材１４を結合したアセンブリを、コア形成用装置のステージ（スライダ１６）に取付ける（ステップＳ６０５）。
（６）上記溝部２Ｇ内に紫外線硬化樹脂を注入し、該注入した紫外線硬化樹脂に紫外線２０を照射し該樹脂を硬化させ、上記クラッド２、上記プラスチックシート材１４よりも光の屈折率が高いコアを構成する（ステップＳ６０６）。
（７）コア形成したものをコア形成用装置のステージ（スライダ１６）から取外し、光導波路ユニットとする（ステップＳ６０７）。
【００１１】
上記第１の実施例によれば、平面や端面を予め所定の精度にした板状部材５と複数のコマ６、７とを組合わせた成形型によりクラッド２を形成するため、（ａ）該クラッド２の溝部２Ｇの側面や底面の面粗さの所定の精度を容易に確保できるとともに、（ｂ）溝部２Ｇの開口部のダレも抑えられる。また、コア３の成形後の加工が不要なため、（ｃ）コア３とクラッド２の溝部２Ｇの内面との間に隙間が生ずることも抑えられる。また、上記図４の装置構成においては、クラッド２の溝部２Ｇ内に紫外線硬化樹脂３’を重力方向に注入して硬化させるため、該樹脂の固化収縮を重力方向すなわち溝部２Ｇの長手方向に発生させることができる。この点からも、コア３とクラッド２の溝部２Ｇの内面との間に隙間が発生するのを抑えることができる。これらの結果として、光伝送損失の増大を抑えられる。（ａ）に関し、表面精度は、例えば、従来技術では平均面粗さが約５０×１０^-9ｍであったものを、上記第１の実施例構成では約５×１０^-9ｍにできる見通しである。また、（ｂ）に関し、溝部２Ｇの開口部のダレ（丸み）は、例えば、従来技術では曲率半径が約５０×１０^-6ｍであったものを、上記第１の実施例構成ではほとんど０にできる見通しである。さらに、（ｃ）に関し、コア３とクラッド２の溝部２Ｇの内面との間の隙間は、例えば、従来技術では約２×１０^-6ｍであったものを、上記第１の実施例構成ではほとんど０にできる見通しである。これら（ａ）、（ｂ）、（ｃ）の改善の結果、光伝送損失は、例えば、従来技術では約１ｄＢ／１０^-2ｍであったものを、上記第１の実施例構成では約０．３ｄＢ／１０^-2ｍにできる見通しである。また、製作も容易かつ安価にできる。製品及び製作過程における部品の信頼性も高められる。
【００１２】
図７、図８は、本発明の第２の実施例の説明図である。
本実施例は、１本の直線状の第１の光導波路と、該第１の光導波路から分岐した曲線条の第２の光導波路を有する光導波路ユニットの場合の例である。図７は、本実施例の光導波路ユニットの第１の部材としてのクラッドを成形するための成形型の平面構成例図、図８は、図７の構成の側面図である。
図７、図８において、２５は、直線状の第１の光導波路を形成するための第１の板状部材、２６は、曲線状の第２の光導波路を形成するための第２の板状部材、２７、２８、２９は、板状部材２５、２６の両面をはさみ固定する固定用部材としてのコマ、２７'は、コマ２７の板状部材２５との接触面側に設けた逃げ部、２８'は、コマ２８の板状部材２５との接触面側に設けた逃げ部、２８''は、コマ２８の板状部材２６との接触面側に設けた逃げ部、２９'は、コマ２９の板状部材２６との接触面側に設けた逃げ部である。板状部材２５、２６及びコマ２７、２８、２９はそれぞれ、端面を含め表面を予め高精度に加工されている。コマ２７、２８、２９の板状部材２５への接触面は長手方向に直線状にされている。このため、板状部材２５はコマ２７、２８、２９によってはさまれ押されて固定された状態においては、該コマ２７、２８、２９の端面から所定の高さで突出した突出部も長手方向に該コマ２７、２８、２９の接触面に沿った直線状となる。一方、コマ２８、２９の板状部材２６への接触面は長手方向に曲線状にされている。このため、板状部材２６はコマ２８、２９によってはさまれ押されて固定された状態においては、該コマ２８、２９の端面から所定の高さで突出した突出部も長手方向に該コマ２８、２９の曲面状接触面に沿った曲線状となる。該コマ２７、２８、２９は、上記第１の実施例の場合と同様、外枠部材と、可動式の押さえ部材とから外力を供給されるようになっている。上記各コマコマ２７、２８、２９の各逃げ部２７'、２８'、２８''、２９'はそれぞれ、押さえ部材と外枠から与えられる外力を該逃げ部の両側の接触面に分配しそれぞれの接触面での板状部材２５、２６との接触の面圧を高めるとともに、板状部材２５、２６それぞれのそり等も吸収する。
本第２の実施例の場合も、上記第１の実施例と同様、図２に示すような成形治具によりクラッドを製作し、図４に示すような装置によりコアを形成して光導波路ユニットを製作する。
【００１３】
上記第２の実施例によれば、上記第１の実施例の場合と同様、平面や端面を予め所定の精度にした板状部材２５、２６と複数のコマ２７、２８、２９とを組合わせた成形型によりクラッドを形成するため、（ａ）該クラッドの溝部の側面や底面の面粗さの所定の精度を容易に確保できるし、また、（ｂ）溝部の開口部のダレも抑えられる。また、コアに対し、成形後の加工が不要なため、（ｃ）コアとクラッドの溝部の内面との間の隙間発生も抑えられる。また、クラッドの溝部内に紫外線硬化樹脂を重力方向に注入して硬化させるようにするため、該樹脂の固化収縮を重力方向すなわち溝部の長手方向に発生させるようにでき、この点からも、コアとクラッドの溝部の内面との間に隙間を発生しにくくすることができる。これらの結果、光伝送損失の増大を抑えられる。（ａ）、（ｂ）、（ｃ）に関しての定量的な改善幅も、上記第１の実施例の場合と同様にできる。また、容易かつ安価に製作でき、かつ信頼性も高められる。
【００１４】
なお、上記各実施例では、コア材として紫外線硬化樹脂を用いたが、本発明はこれに限定されない。光導波路の数や形状、コマ数なども、上記実施例の構成に限定されない。
さらに、本発明の適用範囲は、深さ数十ミクロン以上の光導波路断面を有する光導波路ユニットに限定されない。
【００１５】
【発明の効果】
本発明によれば、光通信用の光導波路ユニットを容易かつ安価に製作でき、光伝送損失の増大も抑えられる。また、信頼性も高められる。
【図面の簡単な説明】
【図１】本発明の第１の実施例におけるクラッド成形型の構成例図である。
【図２】図１の成形型を用いたクラッド成形治具の構成例図である。
【図３】図２の治具で製作したクラッドの外観図である。
【図４】本発明の第１の実施例におけるコア形成用装置の構成例図である。
【図５】図４の装置で製作された光導波路ユニットの断面図である。
【図６】本発明の第１の実施例の光導波路ユニットを製作する手順の例を示すフロー図である。
【図７】本発明の第２の実施例におけるクラッド成形型の平面構成例を示す図である。
【図８】図７のクラッド成形型の側面図である。
【図９】従来技術例を示す図である。
【図１０】従来技術の課題点の説明図である。
【符号の説明】
１…金型、２、２'…クラッド、３…コア、５、２５、２６：板状部材、６、７、２７、２８、２９…コマ、６'、７'、２７'、２８'、２８''、２９'…逃げ部、８…押さえ部材、９…外枠部材、１４…プラスチックシート材、１５…ガラス板、１６…スライダ、１７…支持部材、１９…漏れ止め部材、２０…紫外線、２１…ランプ、２２、２３…遮蔽板、２４…スリット。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical waveguide unit for optical communication coupled to an optical fiber or the like.
[0002]
[Prior art]
Conventionally, glass-based inorganic materials have been used for optical components such as an optical waveguide unit for optical communication coupled to an optical fiber in terms of optical transmission loss and transmission band. Recently, however, plastic materials that are more advantageous than inorganic materials in terms of processability and cost are attracting attention as optical waveguide materials, and various plastic materials and manufacturing methods have been developed. For example, Japanese Patent Application Laid-Open Nos. 8-313747 and 9-189818 describe related technologies that use a plastic material as an optical waveguide material and are manufactured using an exposure technique. Japanese Patent Application Laid-Open No. 63-139304 describes a technique using a mold as a technique for manufacturing an optical waveguide having a large cross-sectional area. FIG. 9 shows an outline of the technique described in the publication. FIGS. 4A to 4E show the manufacturing process of the optical waveguide unit, in which (a) a mold 1 having a partially protruding shape is prepared, and (b) the protruding portion 1a of the mold 1 is transferred. Then, a groove is formed in the clad 2 ′, (c) a core material is injected into the groove and solidified to form the core 3, and (d) the clad 2 ′ is formed so that the clad surface and the core surface are flattened. The optical waveguide unit is manufactured through grinding the surface and (e) adhering the upper clad 4 on the processed surface.
[0003]
[Problems to be solved by the invention]
Among the above-described conventional techniques, in the case of using the exposure technique, there is a risk that the formation of an optical waveguide having a large cross-sectional area with a groove depth of several tens of microns or more may have insufficient accuracy. Further, in the technique using a mold as described in Japanese Patent Application Laid-Open No. 63-139304, since the protrusion 1a of the mold 1 is formed by cutting, the surface roughness of the side surface 1a1 (FIG. 10) of the protrusion 1a. Accuracy cannot be ensured, or the corner 1a2 (FIG. 10) between the root portion of the side surface 1a2 of the projection 1a and the mold plane is rounded, which causes the opening of the groove of the clad 2 'to sag. Or Further, in order to compensate for the solidification shrinkage of the core material, when an excessive amount of liquid core material is injected into the groove of the clad 2 ′, a grinding process for flattening the clad 2 ′ and the core 3 is performed. If post-processing is necessary (FIG. 9D), a gap is likely to be generated between the groove side surface of the clad 2 ′ and the core 3 due to the force applied from the tool during processing. Insufficient surface accuracy such as the side surface 1a1 of the protrusion 1a, sagging of the groove opening due to rounded corners of the base of the protrusion 1a, and a gap between the groove side surface of the clad 2 'and the core 3 These are factors that increase optical transmission loss in the optical waveguide unit.
An object of the present invention is to provide an optical waveguide unit having an optical waveguide cross section with a depth of several tens of microns or more in the optical waveguide unit technology even when a plastic material is used for a core or a clad in the optical waveguide unit technology. It is easy to manufacture at low cost and to suppress an increase in optical transmission loss. For this purpose, it is necessary to ensure the accuracy of the mold for forming the groove of the clad with a simple configuration and to eliminate the need for post-processing of the core.
An object of the present invention is to provide a technique capable of solving such problems.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, basically, as a mold for producing a clad (first member) of an optical waveguide unit, both surfaces of a plate-like member are provided with a plurality of fixing members (coma). ), A structure in which a part of the plate-like member protrudes from the end face of the fixing member is used. As the clad (first member), the protruding portion of the plate member and the end surface of the fixing member are covered with a plastic material, and a groove is formed on the surface of the plastic material by the protruding portion of the plate member. A cured configuration is adopted. Further, after the second member is coupled to the clad (first member) and the groove portion is covered, an ultraviolet curable resin or the like as a core material is injected into the groove portion and cured, so that the optical material incorporating the core material is contained. Set to the state of the waveguide unit. Specifically, (1) a first member (corresponding example: reference numeral 2) having a groove (corresponding example: 2G) and made of a plastic material as an optical waveguide unit, and a light-transmitting material A second member (corresponding example: reference numeral 14) that is coupled to the first member and covers the groove, and is provided in the groove and emits light more than the first member and the second member. And a core (corresponding example: reference numeral 3) made of a plastic material having a high refractive index, and the optical signal is guided through the core of the groove. (2) In the above (1), the core is made of an ultraviolet curable resin. (3) In the above (1), the first member has a configuration in which the average surface roughness of the side surface of the groove is 10 × 10 ⁻⁹ m or less. (4) In the above (1), the second member is made of a plastic material having a refractive index of light substantially equal to that of the first member. (5) As a method for manufacturing an optical waveguide unit, a first step is to place both sides of a plate-like member between a plurality of fixing members so that a part of the plate-like member protrudes from an end surface of the fixing member ( Corresponding Example: Reference numeral S601), the protruding portion of the plate member and the end surface of the fixing member are covered with a plastic material, and a groove portion is formed on the surface of the plastic material by the protruding portion of the plate member. A second step (corresponding example: S602) constituting one member, and a third step (corresponding example: S603) for separating the first member from the plate-like member and the fixing member. And a fourth step of connecting the second member to the first member and covering the groove portion (corresponding example: reference numeral S604), and injecting resin into the groove portion and curing the resin to form a core. Step 5 (corresponding embodiment: symbol S606) Producing an optical waveguide unit through. (6) As a method of manufacturing an optical waveguide unit, a first step of sandwiching both surfaces of a plate-like member with a plurality of fixing members and causing a part of the plate-like member to protrude from an end surface of the fixing member ( Corresponding Example: Reference numeral S601), the protruding portion of the plate member and the end surface of the fixing member are covered with a plastic material, and a groove portion is formed on the surface of the plastic material by the protruding portion of the plate member. A second step (corresponding example: S602) constituting one member, and a third step (corresponding example: S603) for separating the first member from the plate-like member and the fixing member. And a fourth step (corresponding example: reference numeral S604) for joining the second member made of a light transmissive material to the first member and covering the groove, and injecting an ultraviolet curable resin into the groove. UV light is injected into the injected UV curable resin. And curing the resin to form a core having a refractive index of light higher than that of the first member and the second member (corresponding example: reference numeral S606), and the optical waveguide unit. To manufacture. (7) In the above (5) or (6), in the first step, the plate member is fixed by applying an external force to the inclined surface of the fixing member. (8) In the above (5) or (6), in the second step, the protruding portion of the plate-like member and the end surface of the fixing member are covered with the groove portion in a state where the plastic material is heated and softened. After the formation, the plastic material is cooled and cured. (9) In the above (5) or (6), in the fourth step, the second member having a refractive index of light substantially equal to that of the first member is used. (10) In the above (6), in the fifth step, the injected ultraviolet curable resin is irradiated with the ultraviolet light being moved relative to the longitudinal direction of the groove through the second member. (11) As a mold for forming an optical waveguide unit for manufacturing an optical waveguide unit, a plate-like member (corresponding examples: reference numerals 5, 25, 26) and both sides of the plate-like member are sandwiched, and an end portion is a predetermined amount. A plurality of fixing members (corresponding examples: reference numerals 6, 7, 27, 28, 29) for fixing the plate-like member in a protruding state, and a groove portion for an optical waveguide can be formed by the protruding portion. The configuration. (12) In the above (11), each of the fixing members has a relief portion (corresponding examples: reference numerals 6 ′, 7 ′, 27 ′, 28 ′, 28 ′) on the surface side facing the plate member. ', 29'), and is configured to contact the plate-like member on a plurality of surfaces. (13) As an optical communication device provided with an optical waveguide unit, the optical waveguide unit is composed of a first member made of a plastic material having a groove, and is coupled to the first member. And a second member that covers the groove, and a core made of a plastic material that is provided in the groove and has a higher refractive index of light than the first member and the second member. The optical signal is guided through the core of the groove. In each of the above, the plate-like member and the fixing member each have a surface processed in advance with high accuracy including the end face.
The plate-like member forms the groove on the surface of the first member in the molding process. The second member is coupled to the first member to cover the groove and form a space into which the core material is injected, and eliminates the need for post-processing such as grinding of the core after injection.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIGS. 1-6 is explanatory drawing of the 1st Example of this invention.
The present embodiment is an example of an optical waveguide unit having a single linear optical waveguide. FIG. 1 is a configuration example of a molding die for manufacturing a clad as a first member, FIG. 2 is a configuration example of a molding jig when the cladding is manufactured using the molding die of FIG. 1, and FIG. FIG. 4 shows a configuration example of an apparatus for forming a core by injecting and hardening a fluid core material such as a liquid into a groove portion of the manufactured clad. 5 is a cross section of the optical waveguide unit manufactured by the apparatus of FIG. 4, and FIG. 6 is a flowchart showing an example of a procedure for manufacturing the optical waveguide unit.
In FIG. 1, 5 is a plate-like member, 6 and 7 are pieces as fixing members that sandwich and fix both sides of the plate-like member 5, 6 ′ is a relief portion provided on the plate-like member contact surface side of the piece 6, 7 ′ is a relief portion provided on the plate-like member contact surface side of the top 7, 8 is a pressing member that applies an external force to the top 7 via the slope portion 36, and 9 is a top portion of the top 6 via the slope portion 35. It is an outer frame member that gives an external force. The plate-like member 5 and the tops 6 and 7 are processed with high accuracy in advance on the surfaces including the end faces. The contact surfaces of the tops 6 and 7 with the plate-like member 5 are linear in the longitudinal direction. For this reason, when the plate-like member 5 is sandwiched and fixed by the tops 6 and 7, the protruding portion of the plate-like member 5 that protrudes from the end surfaces of the tops 6 and 7 at a predetermined height is also in the longitudinal direction. It becomes a straight line. The holding member 8 applies an external force to the top 7 via the inclined surface portion 36 by moving downward in the drawing. The outer frame member 9 applies an external force to the top 6 via the slope portion 35. Each of the tops 6 and 7 is in contact with both surfaces of the plate-like member 5 with no gap and fixes the plate-like member 5. The escape portion 7 ′ of the top 7 distributes the external force applied from the pressing member 8 to the contact surfaces on both sides of the escape portion 7 ′ and increases the surface pressure of contact with the plate-like member 5 at each contact surface. Similarly, the relief portion 6 ′ of the top 6 distributes the external force applied from the outer frame member 9 to the contact surfaces on both sides of the relief portion 6 ′, and the contact surface pressure with the plate-like member 5 at each contact surface. To increase. The escape portions 6 ′ and 7 ′ also absorb the warpage of the plate-like member.
[0006]
In FIG. 2, 2p is a plastic material for forming a clad as a first member, 10 is a lower substrate, 11 is an upper substrate, 12 is a hole provided in the upper substrate 11, and 13 is a screw. It is. Other parts are the same as those in FIG. As the forming jig, the pressing member 8 is moved downward in the figure by the screw 13 so that an external force is applied to the top 7 through the slope portion 36, and the plate-like member 5 is fixed between the tops 6 and 7. The state is fixed at the position and posture. When the molding jig in such a state is heated and reaches a predetermined temperature, the plastic material 2p is put into the hole 12 of the upper base material 11, and the plastic material 2p is softened by heat and pressed to form a plate-like member. The protruding portion 5 and the end surfaces of the tops 6 and 7 are covered with the plastic material 2p, and then the plastic material 2p is cured by cooling. After the curing, the plastic material 2p is taken out from the molding jig to form the clad 2 as the first member.
[0007]
FIG. 3 shows an appearance of the clad 2 manufactured by the forming jig shown in FIG. The groove 2G is formed by the protruding portion of the plate member 5 and the end surfaces of the tops 6 and 7. In the present embodiment, since the projecting portion of the plate member 5 and the end surfaces of the pieces 6 and 7 are combined in advance with high precision, the groove portion 2G has the groove dimensions and the surface roughness of the side surface and the bottom surface. The flatness and the like are within a predetermined range. For example, if the average surface roughness of the side surface and the bottom surface of the groove 2G is 10 × 10 ⁻⁹ m or less, an increase in optical transmission loss can be suppressed.
[0008]
FIG. 4 is a configuration example of an apparatus for forming a core by injecting a core material into the groove 2G of the clad 2 manufactured and curing the core material. FIG. 4 shows a state when the clad 2 is attached. In FIG. 4, 3 ′ is a liquid ultraviolet curable resin as a core material, 18 is a cylinder that holds the ultraviolet curable resin 3 ′, and 14 is a light transmissive material as a second member that is coupled to the clad 2 and covers the groove 2G. 15 is a glass plate for pressing the plastic sheet material 16, 16 is a slider to which the clad 2 is attached and moves in the vertical direction of the figure, 17 is a support member for supporting the slider 16, 20 is an ultraviolet ray irradiated to cure the ultraviolet curable resin 3 ′, 21 is a lamp as a light source of the ultraviolet ray 20, 22 and 23 are shielding plates, and 24 is a slit formed between the shielding plates 22 and 23. , 19 is a leakage preventing member for preventing leakage of the liquid ultraviolet curable resin injected into the groove 2G, and 3a ′ is not cured of the ultraviolet curable resin injected into the groove 2G. 3b 'is hardened. In this embodiment, the plastic sheet material 14 is made of the same material as the clad 2. As the ultraviolet curable resin, a resin having a higher refractive index than that of the clad 2 or the plastic sheet material 14 is used. In the above configuration, pressure is applied to the cylinder 18 to inject the ultraviolet curable resin 3 ′ into the groove 2G of the clad 2 in the direction of gravity, and ultraviolet light is applied to the ultraviolet curable resin in the groove 2G at the time of injection or after completion of the injection. 20 is irradiated through the glass plate 15 and the plastic sheet material 14 to cure the ultraviolet curable resin. At this time, the ultraviolet rays 20 are partially irradiated to the groove portion 2G of the clad 2 from the slit 24, and the ultraviolet rays 20 are applied to the ultraviolet curable resin in the groove portion 2G by the movement of the slider 16 from the top to the bottom of the figure. Irradiation is sequentially performed from a portion below the groove 2G. Thereby, the ultraviolet curable resin in the groove 2G of the clad 2 is cured in order from the lower side. That is, the core is formed in the longitudinal direction of the groove 2G by replenishing the core material to the upper end of the uncured groove. When an air gap finally occurs at the upper end of the groove, that portion may be cut off. In addition, the size of the slit 24 can be changed by shifting the mutual positions of the shielding plates 22 and 23.
[0009]
FIG. 5 is an external view of an optical waveguide unit manufactured by the apparatus of FIG. In FIG. 5, reference numeral 2 denotes a clad as a first member having a groove portion and made of a plastic material, and 14 is made of a light-transmitting material, and is coupled to the clad 2 to cover the groove portion. A plastic sheet material 3 as a member is a core formed of an ultraviolet curable resin that is provided in the groove portion of the clad 2 and has a higher refractive index of light than the clad 2 and the plastic sheet material 14. The core does not require post-processing after molding.
[0010]
FIG. 6 is a flowchart showing a manufacturing procedure of the optical waveguide unit described with reference to FIGS.
In FIG.
(1) The both sides of the plate-like member 6 are sandwiched between the frames 6 and 7 as a plurality of fixing members so that a part of the plate-like member 5 protrudes from the end surfaces of the pieces 6 and 7 (step S601). . The plate member 5 and the tops 6 and 7 are previously processed with high accuracy. (2) The projecting portion of the plate-like member 5 and the end surfaces of the pieces 6 and 7 are covered with a plastic material by heating, pressurizing, etc. in a forming jig, and the plastic material is covered by the projecting portion of the plate-like member 5. A groove 2G is formed on the surface to constitute the clad 2 as the first member (step S602).
(3) The clad 2 is separated from the plate-like member 5 and the tops 6 and 7 (step S603).
(4) The plastic sheet material 14 as the second member made of a light transmissive material is coupled to the cladding 2 as the first member to cover the groove 2G (step S604).
(5) The assembly in which the plastic sheet material 14 is bonded to the clad 2 is attached to the stage (slider 16) of the core forming apparatus (step S605).
(6) An ultraviolet curable resin is injected into the groove 2G, and the injected ultraviolet curable resin is irradiated with ultraviolet rays 20 to cure the resin, so that the refractive index of light is higher than that of the cladding 2 and the plastic sheet material 14. A core is configured (step S606).
(7) After the core is formed, the core is removed from the stage (slider 16) of the core forming apparatus to obtain an optical waveguide unit (step S607).
[0011]
According to the first embodiment, the clad 2 is formed by the molding die in which the plate-like member 5 whose plane or end surface is previously set to a predetermined accuracy and the plurality of pieces 6 and 7 are combined. The predetermined accuracy of the surface roughness of the side surface and the bottom surface of the groove 2G of the clad 2 can be easily ensured, and (b) sagging of the opening of the groove 2G is also suppressed. Further, since the processing after the core 3 is not required to be formed, it is possible to suppress the occurrence of a gap between (c) the core 3 and the inner surface of the groove portion 2G of the clad 2. In the apparatus configuration shown in FIG. 4, since the ultraviolet curable resin 3 'is injected into the groove 2G of the clad 2 in the direction of gravity and hardened, solidification shrinkage of the resin occurs in the direction of gravity, that is, the longitudinal direction of the groove 2G. Can be made. Also from this point, generation of a gap between the core 3 and the inner surface of the groove 2G of the clad 2 can be suppressed. As a result, an increase in optical transmission loss can be suppressed. With regard to (a), for example, the surface accuracy is expected to be about 5 × 10 ⁻⁹ m in the first embodiment, compared with the average surface roughness of about 50 × 10 ⁻⁹ m in the prior art. It is. Regarding (b), the sag (roundness) of the opening of the groove 2G is, for example, approximately 0 × 10 × ^{6 −6} m in the prior art, and almost 0 in the configuration of the first embodiment. It is a prospect that can be done. Further, with respect to (c), the gap between the core 3 and the inner surface of the groove 2G of the clad 2 is, for example, about 2 × 10 ⁻⁶ m in the prior art, The prospect is almost zero. As a result of the improvement of (a), (b), and (c), the optical transmission loss is, for example, about 1 dB / 10 ⁻² m in the prior art, and about 0 in the configuration of the first embodiment. It is expected to be 3 dB / 10 ^-2 m. Moreover, it can be manufactured easily and inexpensively. The reliability of products and parts in the manufacturing process is also increased.
[0012]
7 and 8 are explanatory diagrams of the second embodiment of the present invention.
The present embodiment is an example of an optical waveguide unit having one linear first optical waveguide and a curved second optical waveguide branched from the first optical waveguide. FIG. 7 is a plan configuration diagram of a molding die for molding a clad as a first member of the optical waveguide unit of the present embodiment, and FIG. 8 is a side view of the configuration of FIG.
7 and 8, 25 is a first plate member for forming a linear first optical waveguide, and 26 is a second plate for forming a curved second optical waveguide. 27, 28, 29 are pieces as fixing members for fixing both surfaces of the plate-like members 25, 26, and 27 ′ is a relief portion provided on the contact surface side of the piece 27 with the plate-like member 25 , 28 ′ is a relief portion provided on the contact surface side of the piece 28 with the plate-like member 25, 28 ″ is a relief portion provided on the contact surface side of the piece 28 with the plate-like member 26, and 29 ′ is This is an escape portion provided on the contact surface side of the top 29 with the plate-like member 26. The plate-like members 25 and 26 and the tops 27, 28, and 29 have their surfaces processed in advance with high accuracy, including the end faces. The contact surfaces of the tops 27, 28 and 29 with the plate-like member 25 are linear in the longitudinal direction. Therefore, in a state where the plate-like member 25 is sandwiched and pressed by the frames 27, 28, 29, the protruding portion protruding at a predetermined height from the end face of the frames 27, 28, 29 is also in the longitudinal direction. Further, it becomes a straight line along the contact surface of the frames 27, 28 and 29. On the other hand, the contact surfaces of the tops 28 and 29 with the plate-like member 26 are curved in the longitudinal direction. For this reason, in a state where the plate-like member 26 is sandwiched and pressed by the tops 28 and 29 and fixed, the projecting portion that protrudes from the end face of the tops 28 and 29 at a predetermined height also extends in the longitudinal direction. , 29 are curved along the curved contact surface. As in the case of the first embodiment, the frames 27, 28, 29 are supplied with external force from the outer frame member and the movable pressing member. The relief portions 27 ′, 28 ′, 28 ″, 29 ′ of the top pieces 27, 28, 29 distribute the external force applied from the pressing member and the outer frame to the contact surfaces on both sides of the relief portion, respectively. While increasing the surface pressure of contact with the plate-like members 25 and 26 at the contact surface, the warp of the plate-like members 25 and 26 is also absorbed.
Also in the case of the second embodiment, as in the first embodiment, a clad is manufactured by a forming jig as shown in FIG. 2, and a core is formed by an apparatus as shown in FIG. Is produced.
[0013]
According to the second embodiment, as in the case of the first embodiment, the plate-like members 25 and 26 whose planes and end faces are set to predetermined accuracy in advance and the plurality of pieces 27, 28 and 29 are combined. Since the clad is formed by the forming mold, (a) the predetermined accuracy of the surface roughness of the side surface and the bottom surface of the groove portion of the clad can be easily secured, and (b) the sagging of the opening portion of the groove portion can be suppressed. . Moreover, since the post-molding process is not required for the core, (c) generation of a gap between the core and the inner surface of the groove of the clad can be suppressed. In addition, in order to cure the resin by injecting UV curable resin into the groove of the clad in the direction of gravity, solidification shrinkage of the resin can be generated in the direction of gravity, that is, in the longitudinal direction of the groove. It is possible to make it difficult to generate a gap between the inner surface of the groove portion of the clad. As a result, an increase in optical transmission loss can be suppressed. Quantitative improvements for (a), (b), and (c) can also be made in the same manner as in the first embodiment. Further, it can be manufactured easily and inexpensively and the reliability is improved.
[0014]
In each of the above embodiments, an ultraviolet curable resin is used as the core material, but the present invention is not limited to this. The number and shape of the optical waveguides, the number of frames, etc. are not limited to the configuration of the above embodiment.
Furthermore, the application range of the present invention is not limited to an optical waveguide unit having an optical waveguide cross section with a depth of several tens of microns or more.
[0015]
【The invention's effect】
According to the present invention, an optical waveguide unit for optical communication can be easily and inexpensively manufactured, and an increase in optical transmission loss can be suppressed. In addition, reliability is improved.
[Brief description of the drawings]
FIG. 1 is a configuration example diagram of a cladding mold according to a first embodiment of the present invention.
2 is a configuration example diagram of a clad forming jig using the forming die of FIG. 1;
FIG. 3 is an external view of a clad manufactured by the jig shown in FIG.
FIG. 4 is a configuration diagram of a core forming apparatus according to the first embodiment of the present invention.
5 is a cross-sectional view of an optical waveguide unit manufactured by the apparatus of FIG.
FIG. 6 is a flowchart showing an example of a procedure for manufacturing the optical waveguide unit according to the first embodiment of the present invention.
FIG. 7 is a diagram showing an example of a planar configuration of a cladding mold according to a second embodiment of the present invention.
8 is a side view of the cladding mold shown in FIG. 7. FIG.
FIG. 9 is a diagram illustrating an example of a conventional technique.
FIG. 10 is an explanatory diagram of problems of the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Mold, 2, 2 '... Cladding, 3 ... Core, 5, 25, 26: Plate member, 6, 7, 27, 28, 29 ... Top, 6', 7 ', 27', 28 ', 28 '', 29 '... relief part, 8 ... pressing member, 9 ... outer frame member, 14 ... plastic sheet material, 15 ... glass plate, 16 ... slider, 17 ... support member, 19 ... leak-proof member, 20 ... ultraviolet ray 21 ... Lamp, 22, 23 ... Shield plate, 24 ... Slit.

Claims

A method of manufacturing an optical waveguide unit for optical communication in which a core is formed in a groove provided in a clad main surface ,
A plurality of fixing members having a plate-like member having a pair of main surfaces facing each other and end surfaces in contact with the pair of main surfaces at one end thereof, and a first surface and a second surface in contact with one end of the first surface The plate-like member is sandwiched between the plurality of fixing members by applying the first surfaces of the plurality of fixing members to each of the pair of main surfaces of the plate-like member. A first step of assembling a forming jig by projecting each of the end surfaces of the first and second ends of the pair of main surfaces from the second surface of the fixing member;
The plastic material for forming the clad is heated by heating the forming jig, and the plastic material is pressed to protrude the second surface of the plurality of fixing members and the plate shape protruding from the second surface. Covering the one end of the member with the plastic material, and then curing the plastic material to form a groove formed by the one end of the plate-like member on the surface formed by the second surface of the plurality of fixing members. A second step of forming the cladding having:
A third step of separating the cladding from the forming jig;
The surface of the clad is bonded to a plastic sheet material to cover the first opening of the groove portion on the surface, and the second opening at one end of the groove portion defined by the clad surface and the plastic sheet material is a leakage preventing member A fourth step of closing with
The clad is disposed so that the one end of the groove portion is located below, and resin is introduced into the groove portion from the third opening at the other end of the groove portion defined by the clad surface and the plastic sheet material in the direction of gravity. A fifth step of injecting and filling the groove with resin, and sequentially curing the resin from the one end to the other end of the groove to constitute the core;
A method for manufacturing an optical waveguide unit, wherein the steps are performed in this order .

The plastic sheet material is made of a light transmissive material,
Using an ultraviolet curable resin as the resin,
In the fifth step, the resin injected into the groove is cured by irradiating ultraviolet rays through the plastic sheet material to form the core having a higher refractive index of light than the clad and the plastic sheet material. The method for manufacturing an optical waveguide unit according to claim 1.

In the first step, according to claim 1 or claim 2 wherein the plate-shaped member by applying an external force to the inclined surface portion facing the first surface of the fixing member for fixing at said first surface of said fixing member The manufacturing method of the optical waveguide unit of description.

The method for manufacturing an optical waveguide unit according to any one of claims 1 to 3, wherein a material having a refractive index of light substantially equal to that of the cladding is used as the plastic sheet material .

In the fifth step, the plastic is injected into the resin injected into the groove while moving the ultraviolet light relative to the groove from one end in the extending direction toward the other end in the extending direction. The manufacturing method of the optical waveguide unit of Claim 2 irradiated through a sheet | seat material .

An optical waveguide unit molding die for molding the clad main surface of an optical waveguide unit for optical communication in which an optical waveguide groove provided on the clad main surface is formed ,
A plate-shaped member having a pair of main surfaces facing each other and end surfaces in contact with the pair of main surfaces at one end thereof;
A plurality of fixing members having a first surface and a second surface in contact with one end of the first surface;
The plate-like member and the plurality of fixing members are arranged such that the first surfaces of the plurality of fixing members are respectively applied to the pair of main surfaces of the plate-like member. And the end surface of the plate-like member and each of the portions on the one end side of the pair of main surfaces protrude from the second surfaces of the plurality of fixing members of the fixing member, respectively. The plastic material constituting the cladding is softened and pressed with the second surface of the fixing member and the one end of the plate member,
The second surface of the plurality of fixing members, the end surface forming the one end of the plate-like member protruding from the second surface, and a part of the main surface are cured of the plastic material covering the processing surface Determine the shape of the cladding main surface and the groove formed in
An optical waveguide unit molding die , wherein relief portions are respectively formed in portions of the first surfaces of the plurality of fixing members that are brought into contact with the main surface of the plate-like member .