JP3824663B2 - Optical cable having a plurality of wave light guides - Google Patents

Description

【００２９】
レーレー散乱による減衰
α_Ｓ＝（０．６８５＋６６Δｎ）／λ^４ （５）
次の屈折率の場合は次の値から出発する：
Ｖｃ＝２．４０５
λｃ＝λ_ｃｅｆｆ＋１００ｎｍ（λｃ＝理論上の限界波長）
ｎ_１＝１．４５１；ただしλ＝１３００ｎｍ
（１）〜（４）により次の式が得られる。
【００３０】
Δ＝（１／２π^２）（λｃＶｃ／ＭＡＣ・λ_ｃｅｆｆ・ｎ_１）…０.６５＋１.６１９
／（λｃＶｃ／λ）・＋・２.８７９／（λｃＶｃ／λ）
正規化された屈折率差△を屈折率差△ｎに変換してその結果を（５）に代入すると、図６に示されている、λ_ｃｅｆｆの関数としての減衰α_ｓの依存性が、種々のＭＡＣ値の場合に得られる。曲線Ｋ１はＭＡＣ＝６．５、曲線Ｋ２はＭＡＣ＝７、曲線Ｋ３はＭＡＣ＝７．５の場合にそれぞれ当てはまる。
【００３１】
図６に示されている様にＭＡＣ＝６．５の場合でさえもキロメータ減衰（１３００ｎｍの場合）はまだ０．４ｄＢ／ｋｍよりも小さい。ＭＡＣ＝７．５の場合の減衰値に比べて、減衰はわずか約５・１０~^２ｄＢ／ｋｍしか増加しない。しかしマイクロ屈折感応度は著しく低減している。
【００３２】
そのためこの種のファイバーは例えば、ファイバーが著しく大きいマイクロ屈折を受けるような、ケーブル構造の位置に適する。
【００３３】
図７は、図１に示されているＵ形プロフィルのケーブルの中に設けられている、１０個のファイバー帯状体を有する帯状体成層体から成る、上側、中間および下側の波光導体Ｌ１−Ｌ１２の減衰値αを示す。
【００３４】
破線は荷重の加わらない状態におけるファイバー帯状体の減衰値を示す。即ち全部の波光導体Ｌ１−Ｌ１２は、波長１５５０ｎｍの場合にだいたい同じ減衰度０．２ｄＢ／ｋｍを有する。マイクロ屈曲感応度の大きいファイバーが用いられると、前述の荷重の場合たとえばより線化そのものの場合またはケーブルの内部温度テストの場合、外側帯状体のいちばん外側の両方の波光導体に対する減衰が著しく増加し、白丸ＥＬ１およびＥＬ１２により示されている値にある。即ち減衰増加は約１．０ｄＢ／ｋｍの値を有する。この場合、ＭＡＣ値８．２が定められている。他方、いちばん外側の両方の波光導体Ｌ１とＬ１２のために、マイクロ屈曲感応度の小さいＭＡＣ値６．８のファイバーが用いられる時は、外側の両方の波光導体における減衰増加は著しくわずかで、点ＵＬ１（約０．３３ｄＢ／ｋｍ）と点ＵＬ１２（約０．４５ｄＢ／ｋｍ）により示されている値にしか達しない。
【００３５】
そのためストラクチャの臨界領域にほとんどマイクロ屈曲感応度の小さい波光導体を本発明により使用することにより、ストラクチャの特性全体の著しい改善が達成される。詳細には次の点が改善される：
このストラクチャの維持の下に全体的により小さい減衰値が得られる。
【００３６】
所定の減衰値の場合は不利な処理パラメータ（より大きい屈曲、より小さい区間長さ）が許容できる。
【００３７】
処理パラメータおよび減衰が変らない場合は、ストラクチャの内部でより多くの本数の波光導体が設置できる。
【００３８】
１つの成層体の内部の１つの帯状体の内部にわずか６つの波光導体ではなく、１つの帯状体の内部に８つの波光導体の成層体を、許容される誤差の値を上回わることなく、実現できる。
【００３９】
１つの所定のストラクチャの内部に、わずかしか屈曲感応度を有しない全部の波光導体を構成することもできる、即ちＭＡＣ値７．４を有利に７．０を、必要に応じて６．５さえも下回わるＭＡＣ値で全部の波光導体を構成することもできる。
【００４０】
実際の所与条件たとえば維持されるべき寸法選定は、ストラクチャ内部で最も強く荷重を受ける領域において、機械的にマイクロ屈曲感応度の小さい波光導体を有するストラクチャを構成する場合は、必ずしもそのまま考慮しなくてよい。そのため本発明の別の構成の課題は、種々異なるマイクロ屈曲感応度の波光導体を有する所定のストラクチャを、実際の所与条件の十分な考慮の下に、簡単に構成する手段を提供することである。この課題はこの変形実施例の第１の解決手段により次のようにして解決されている。即ちより高い機械的荷重の領域における波光導体は、その１次コーティングの層の厚さを、より低い機械的荷重の領域における波光導体よりも、より大きくすることにより、解決されている。
【００４１】
それぞれより高い機械的荷重の領域における波光導体の第１の被覆スリーブ（１次コーティング）の厚さ増加により、波光導体の伝送特性における許容できないほど高い減衰増加を生ぜさせるおそれのある、これらのマイクロ−および／またはマクロ屈曲の影響（いわゆる“マイクロ−またはマクロベンディング”）はほとんど受けない様になる。何故ならば１次コーティングの厚さ増加により有利に、例えば発生し得る機械的荷重たとえば圧縮荷重に対して付加的な減衰作用を与えるからである。さらにこの種の波光導体は実際の所与条件に著しく簡単に適合化される種々の変形可能なストラクチャ構成を可能にする。何故ならばそれぞれの波光導体の１次被覆の厚さを所期のように調整することにより、ストラクチャの例えば所定のスペース状態、値選定データ、各々の波光導体への最大許容圧縮力等を、ストラクチャ構成の際に著しく簡単に有利に考慮できるからである。
【００４２】
変形実施例の第２の解決手段によれば、前述の課題は次のようにして解決されている。即ちそれぞれより高い機械的荷重の領域における波光導体が、より低い機械的荷重の領域における波光導体よりも、その第１の被覆のためによりソフトな材料を有することにより解決されている。
【００４３】
この有利な構成によりストラクチャ内部のより高い機械的荷重の個所における波光導体に対しても、許容されない位に高い伝送減衰が回避される。外径直径が同じ場合は、１次コーティング用のよりソフトな材料を有するより強く荷重の加わる波光導体は、わずかな荷重しか加わらない波光導体よりも、良好にクッション作用を受ける、即ち機械的に減衰される。このようにして、種々の所与条件に適合される最適化されたストラクチャ構成が可能になる。
【００４４】
より強く荷重の加わる波光導体の１次コーティングのために、機械的にわずかしか荷重の加わらない波光導体の１次コーティングのためよりも、より大きい１次被覆の厚さ（１次コーティング）ならびに同時によりソフトな材料を設けることは特に有利である。この組み合わされた構成により、種々の所与条件を、たとえば値選定データ、機械的な最小荷重（けんろう性）、各々の個々の波光導体のための許容通過減衰等を満たすストラクチャが著しく簡単に構成される。
【００４５】
荷重が生ずると、図１の帯状体成層体ＳＴ１は実質的に、室空間における角部の４つのファイバーＵ１１１，Ｕ１１４，Ｕ１３１，Ｕ１３４により実質的に支持される。この角部の形式の減衰増加の目的で、必要に応じて例えば温度サイクル、屈曲−または横方向圧力検査が実施できる、即ち成層体の中で角部のファイバーは最も感応度が大きい。
【００４６】
ストラクチャの波光導体の所望の不感応度−例えばそれらの４つの角部領域における−は次のようにして得られる、即ちより高い機械的荷重の個所における光案内ファイバーの被覆の設計（コーティング設計）は、より低い機械的荷重の領域における光案内ファイバーのそれに比較して、変形されていることにより得られる。図１２は、波光導体ＬＷ１＊の構造を示す。これは例えば図１のストラクチャＳＴ１における機械的にマイクロ屈曲感応度の小さい波光導体Ｕ１１１〜Ｕ１３４のために使用できる。図１２の波光導体ＬＷ１＊は中心に光案内用ガラスコアＣＯを有する。ＣＯは外装ガラス（“被覆”）ＣＬにより囲まれている。その結果、外径ＤＦを有する光案内ファイバーが形成されている。この光案内ファイバーの上に少なくとも１つの１次の内側のプラスチック被覆（１次コーティング）ＰＣが被着されている。この１次コーティングＰＣのために例えば、弾性係数０．５〜２．５ＭＰａを有するウレタンアクリラートのようなソフトな材料が選定される。この１次コーティングＰＣはさらに少なくとも１つの２次の、さらに外側に設けられる被覆（２次コーティング）により被われる。この２次コーティングＳＣのために１次コーティング用よりも硬い材料たとえばＳＣ、ウレタンアクリラートまたはシリコンアクリラートエポキシダクリラート−弾性係数５００〜１５００ＭＰａ−が、１次コーティングＰＣの外側表面の損傷を実質的に回避する目的で、さらにこの回避により光案内ファイバーの確実な問題のない以後の処理を可能にする目的で、選定される。
【００４７】
より高い機械的荷重の個所における波光導体たとえば図１のＵ１１１〜Ｕ１３４をそのストラクチャＳＴ１の内部で、使用し得る圧力に対して機械的により非感応しないようにする目的で、波光導体の被覆は次のように形成される。即ち被覆は、小さい機械的荷重の個所における波光導体たとえばＥ１１２〜Ｅ１３３よりも、大きい層の厚さを有する１次コーティングをそれぞれ有するように、形成される。その根拠は、“Ｉｎｔｅｒｎａｔｉｏｎａｌ Ｗｉｒｅ ｕｎｄ Ｃａｂｌｅ Ｓｙｍｐｏｓｉｏｎ Ｐｒｏｃｅｅｄｉｎｇｓ”（ＩＷＣＳ）、１９９３、３８９〜３９０頁に示されている様に第一に、１次コーティングＰＣが波光導体のマイクロ屈曲感応度に影響を与えるからである。たとえばより高い機械的圧力荷重の領域における波光導体Ｕ１１１〜Ｕ１３４がより小さい機械的荷重の領域における例えば図１のＥ１１２〜Ｅ１３３のような波光導体よりも、それぞれ１．５〜４倍たとえば２〜３倍大きい、その１次コーティングＰＣの層の厚さを有する。有利には機械的に感応度のより小さい波光導体の１次コーティングＰＣのために、層の厚さ２０〜５０μｍたとえば３０〜４０μｍが選定される。例えばソフトな１次コーティングＰＣの厚さ増加によりそのクッション作用すなわちバッファ作用が増加する。そのため作用し得る、それぞれの光案内ファイバーへの押圧荷重が減衰されて、全体的により堅ろうな波光導体が形成される。
【００４８】
１次コーティングＰＣの設けられた、図１２の波光導体ＬＷ１＊の光案内ファイバーは例えば、図１のＥ１１２〜Ｅ１３３のような機械的にマイクロ屈曲感応度の大きい波光導体よりも、１．１〜１．５倍たとえば１．２〜１．４倍大きい外径ＤＰＣを有する。例えば外径ＤＰＣは１６５〜２５０μｍ、例えば１７０〜２１０μｍが選定される。より小さいマイクロ屈曲感応度の図１の波光導体Ｕ１１１〜Ｕ１３４の場合の２次コーティングＳＣは、より小さい機械的荷重の図１の波光導体Ｅ１１２〜Ｅ１３３の２次コーティングに比較して、ほぼ等しいかまたは１．１〜２倍大きい層の厚さをそれぞれ有する。有利には２次コーティングＳＣのための層の厚さは１０〜４０μｍたとえば２０〜３０μｍに選定される。そのため圧縮荷重に対して機械的にけんろうな波光導体ＬＷ１＊は、図１の機械的にマイクロ屈曲感応度の大きい波光導体Ｅ１１２〜Ｅ１３３よりも、１．２〜１．８倍たとえば１．２〜１．５倍大きい全体の外径を有する。例えば全体の外径ＤＬＷは２００〜３００μｍたとえば２００〜２５０μｍに選定される。
【００４９】
それぞれの波光導体のマイクロ屈曲感応度への１次コーティングＰＣの影響を説明するために、次のテーブルに例えば波光導体の５つの異なるコーティング形式Ｔ１〜Ｔ５が示されている。
【００５０】
これらは、例えば“Ｉｎｔｅｒｎａｔｉｏｎａｌ Ｗｉｒｅ ｕｎｄ Ｃａｂｌｅ Ｓｙｍｐｏｓｉｕｍ（ＩＷＣＳ）Ｐｒｏｃｅｅｄｉｎｇｓ、１９８９、第４５０頁に示されている、いわゆる“メッシュワイヤテスト”を受ける。それぞれの光導体形式Ｔ１〜Ｔ５に、個々にそれぞれ全体の外径ＤＬＷ、光案内ファイバー直径ＤＦ、外径ＤＰＣ、１次コーティングＰＣで被覆された光案内ファイバー、ならびに１次コーティングＰＣおよび２次コーティングＳＣに対してそれらの所属の弾性係数が示されている。
【００５１】
テーブル１
ＤＬＷ ＤＰＣ ＤＦ コーティング PCの弾性係数 ＳＣ
[μｍ] [μｍ] [μｍ] 機種 ［ＭＰａ］ ［ＭＰａ］
180 150 125 Ｔ1 1.6 1530
200 150 125 Ｔ2 1.6 1530
200 165 125 Ｔ3 1.6 1530
245 205 125 Ｔ4 2.6 690
245 190 125 Ｔ5 1.6 580
図１３に例えば５つの異なるコーティングされた波光導体Ｔ１〜Ｔ５に対してそれぞれ、マイクロ屈曲損失（減衰損失）α＊ｄＢ／ｋｇ圧縮荷重がそれぞれのいわゆるＭＡＣ値に依存して、波長１５５０ｎｍにおいてＭＡＣ領域たとえば６．５〜８．５にわたり示されている。ＭＡＣ値は、ＩＷＣＳ、Ｐｒｏｃｅｅｄｉｎｇｓ１９８８、第７０４〜７０９頁に示されている様に、ファイバーすなわち波光導体のマイクロ感応度を特徴づける。次に関連事項の説明のためにＭＡＣ値を用いる。この場合、次の式が適用される：
ＭＡＣ＝ＭＦＤ／λ_ｃｅｆｆ
この式に示されている様に、それぞれの波光導体のモードフィールド直径ＭＦＤが小さくなると、屈曲感応度は減少する。図１３にＴ１＊で示されている、テーブル１のコーティング形式Ｔ１の場合の測定直線は、現行のモノモード波光導体の場合のマイクロ屈曲損失にもとづく減衰比を、ＭＡＣ値に依存して示す。この１次コーティング形式Ｔ１に比較して２次コーティング形式Ｔ２の場合は、２次コーティングが約２０μｍだけ増加する。このことは図１３の減衰ダイヤグラムにおいて、測定直線Ｔ１をわずかに下回わる測定直線Ｔ２＊を生ぜしめる。他方、伝送減衰の著しく大きい低減ないし低下は、１次コーティング層の厚さ増加により達せられる。このことは例えばコーティング形式Ｔ３−その測定直線Ｔ３＊は約０．０５ｄＢ／ｋｇ（１測定単位）の間隔で測定直線Ｔ２＊を下回わりかつこれにほぼ平行に走行する。図１３にさらにテーブル１のコーティング形式の場合の測定直線Ｔ４＊が示されている。この直線は測定曲線Ｔ３＊を著しく下回わりかつＴ３＊よりも小さい傾きで走行する。コーティング形式Ｔ４はコーティング形式Ｔ３よりも、１次コーティングのより大きい層厚（ＤＰＣ−ＤＦ＝８０μｍ）により特徴づけられている。同時にその２次コーティングＰＣの場合は、この実施例においてはより小さい例えば半分よりも小さい弾性係数を有する材料が選定されている。このコーティングＴ４の設計の場合、減衰損失の一層の低減が達せられる。このことは測定曲線Ｔ３＊よりも小さい傾きで走行する測定直線Ｔ４＊で当該の６．５〜８．５のＭＡＣ領域において示されている。コーティング形式Ｔ５の場合、最終的に波光導体はＭＡＣ値領域６．５〜８．５において外側の圧縮荷重に近似的に依存しないようにできる。このことは例えば、１次コーティングＰＣの弾性係数を形式Ｔ４の弾性係数よりも減少させることにより、達せられる。このことは、Ｔ４＊下側を近似的に一定の形で走行する測定曲線Ｔ５＊に示されている。
【００５２】
１次コーティングの層の厚さの増加に付加的にまたはこれに依存することなく、より高い機械的荷重たとえば押圧力の個所に位置定めされている波光導体の場合に、例えば図１のＵ１１１〜Ｕ１３４の場合に、これらは必要に応じて次のようにしても圧力に一層マイクロ屈曲感応度の大きいように即ち一層けんろうにされる。即ちその１次コーティングＰＣのために、図１のストラクチャＳＴ１の内部のより小さい機械的荷重の範囲における波光導体たとえばＥ１１２〜Ｅ１３３のＰＣのためよりも、よりソフトな材料が選定されていることにより、圧力に一層マイクロ屈曲感応度の大きいように即ち一層けんろうにできる。そのため有利に、より高い機械的荷重の領域における図１の例えばＵ１１１〜Ｕ１３４のような波光導体は、より小さい機械的荷重の領域における波光導体よりもできるだけ小さい弾性係数を有するようにする。例えば図１の強く荷重を受ける波光導体の１次コーティングＰＣのために、それぞれより小さい機械的荷重の領域における図１の波光導体Ｅ１１２〜Ｅ１３３のための材料よりも１〜５倍たとえば１〜２．５倍ソフトな材料が選定されている。特に有利に図１のより強く荷重を受ける波光導体Ｕ１１１〜Ｕ１３４の１次コーティングのために、より小さい荷重の領域における波光導体のための弾性係数よりも、例えば１〜２．５倍小さい弾性係数が選定されている。好適には図１の一層けんろうな光導体Ｕ１１１〜Ｕ１３４は、弾性係数０．５〜３たとえば１〜２ＭＰａを有する。この構成に付加的にまたはこれに依存することなく、より高い圧力荷重の領域における波光導体は、必要に応じて次のようにしても圧力に一層感応させることができる。即ち２次コーティングのために、より小さい荷重を受ける光導体の材料よりもソフトな材料を選定することにより、圧力に一層感応させることができる。有利には一層けんろうな波光導体Ｕ１１１〜Ｕ１３４の２次コーティングのための弾性係数は、機械的によりマイクロ屈曲感応度の大きい波光導体Ｅ１１２〜Ｅ１１３の場合の弾性係数よりも１．０〜２．５倍たとえば１．０〜２．０倍大きく選定される。例えば機械的に圧力に対してより安定している波光導体Ｕ１１１〜Ｕ１３４のための２次コーティングは、弾性係数５００〜１６００ＭＰａたとえば８００〜１５００ＭＰａを有する。そのため２次コーティングは有利に保護層として作用する。そのため外力は２次コーティングＳＣから内側コーティング（１次コーティング）ＰＣの面へ伝達できる。
【００５３】
そのため２次コーティングの弾性係数の影響は１次コーティングの影響に比較して、実質的に無視できる。
【００５４】
そのためテーブル１におけるコーティング形式Ｔ３〜Ｔ５を有する波光導体は約６．５〜８．５のＭＡＣ値領域において、コーティング形式Ｔ１に相応するように通常のように値の選定された波光導体よりも小さいマイクロ屈曲損失を有する。そのためこの種の修正された波光導体は、生じ得る押圧力の作用する、図１のストラクチャＳＴ１の個所に位置定めされる。図１の実施例においてこの位置は例えば帯状体成層体における４つの角部の位置である。しかし特に確実に全部の帯状体Ｂ１１，Ｂ１２及びＢ１３の場合、図１の帯状体成層体において、それぞれ角部の位置においてこの種の圧力感応性の波光導体を設けることもできる。
【００５５】
図８は図１のストラクチャＳＴ１の基本ユニットとしての波光導体帯状体ＢＬ１を示す。この帯状体ＢＬ１は、図１の、いちばん下に位置するＢ１３の場所だけを、およびまたは図１の帯状体成層体（ストラクチャＳＴ１）のいちばん上に位置する帯状体Ｂ１１の場所だけを占める。他方その中間に取り付けられたその他の帯状体は、それぞれ同種の波光導体を有する従来の設計による帯状体とすることができる。しかしこれに代替的に図１の成層体ＳＴ１において全部の帯状体をＢＬ１の形式で即ち同じ形式で構成できる。この代替形式は、一体的な複数式スプライス装置を使用できる利点を有する。
【００５６】
帯状体ＢＬ１はほぼ長方形の長らなプラスチック外側被覆ＡＨ１ならびにそれぞれ少なくとも１つの別の付加的な波光導体ＬＷ１＊，ＬＷｎ＊を有する波光導体標準帯状体ＧＢから構成される。後者はそれぞれ標準帯状体ＧＢの丸められた短辺に外側に長手方向に接続手段ＶＭを用いて外被ＡＨ１へ別個に当接されている。そのためｎ個の波光導体ＬＷ１〜ＬＷｎは標準帯状体ＧＢの外被ＡＨ１の中に埋め込まれて２つの別個の波光導体ＬＷ１＊，ＬＷｎ＊により側面が限定され、その結果、標準帯状体ＧＢよりも広幅の帯状体ＢＬ１が形成される。この場合、波光導体ＬＷ１〜ＬＷｎは仮想の直線状の接続線に沿って外被ＡＨ１の中心に収容される。他方、両方の波光導体ＬＷ１＊，ＬＷｎ＊は外側の保護被覆なしにこの仮想の接続線の両側に続く。別個の付加的な波光導体ＬＷ１＊，ＬＷｎ＊は図８において、標準帯状体ＧＢの波光導体ＬＷ１〜ＬＷｎよりも大きい直径で示されている。このことは次のことを意味する。即ち図８において波光導体ＬＷ１＊，ＬＷｎ＊として前述の様に例えば波光導体Ｕ１１１〜Ｕ１３４のために、この種のものが設けられている。有利にこれらの両方の波光導体ＬＷ１＊，ＬＷｎ＊は、内側に位置するために小さい圧縮荷重を受ける波光導体ＬＷ１〜ＬＷｎよりも大きい、その１次コーティングの層厚を有する（例えばテーブル１のコーティング形式Ｔ３に相応する波光導体）。もちろん全部の別の前述の波光導体形式（コアおよび外装周期に対する異なる屈折率、即ち異なるＭＡＣ値）ならびに生じえる押圧力にマイクロ屈曲感応度の小さい波光導体ＬＷ１＊，ＬＷｎ＊、例えば有利にテーブル１のコーティング形式Ｔ３，Ｔ４，Ｔ５に相応する波光導体のためのコーティング設計も使用できる。波光導体ＬＷ１＊，ＬＷｎ＊のための接続手段ＶＭとして例えば、接着剤、通常の帯状体コーティングまたはその他の粘着手段を選択できる。
【００５７】
図８に、標準帯状体ＧＢを側面で限定する波光導体ＬＷ１＊，ＬＷｎ＊は、内側に位置する波光導体ＬＷ１〜ＬＷｎのための側縁保護の形式で作用する。そのためこれらはまさに、帯状体ＢＬ１の内部で、発生し得る押圧力を最も強く受ける個所に、即ち帯状体ＢＬ１の端部に設けられる。図１の帯状体ＢＬ１において両方の最も外側に設けられている波光導体ＬＷ１＊，ＬＷｎ＊だけがそれぞれその１次コーティングの外被を有するため、それにもかかわらず全体として、外被ＡＨ１の内部でｎ＋２個の同種の波光導体を備えた標準帯状体が有するのとほぼ同じ帯状体量が維持される。このようにして、２つの異なる種類の波光導体を有する著しくコンパクトな帯状体ＢＬ１が形成される。外被ＡＨ１により画定された内側領域における小形の圧力に安定な波光導体ＬＷ１〜ＬＷｎならびに、標準帯状体ＧＢの狭辺における、生じ得る荷重を受ける外側領域の中のこれらに対向する少なくとも２つの圧力に一層安定な波光導体ＬＷ１＊，ＬＷｎ＊。そのためこの帯状体ＢＬ１は著しく高い集約密度によりならびに著しく簡単な製造により特徴づけられる。さらに製造の際に有利に帯状体中での一様なファイバー位置が可能にされる。
【００５８】
図９の波光導体帯状体ＢＬ２の場合、図８の帯状体ＢＬ１との相違は、両方の波光導体ＬＷ１，ＬＷｎ＊がそれぞれ外被ＡＨ１の短辺の角部位置の中に片側で一体化されている点にある。波光導体ＬＷ１＊，ＬＷ２＊はその外側輪郭が帯状体ＢＬ２のための丸められた短辺を形成する。（図８からそのまま取り出された部品は図９において同じ参照記号で示されている）。波光導体ＬＷ１＊，ＬＷ２＊は、帯状体の厚さに相応する外径を有する。そのため波光導体は外被ＡＨ１の短辺のための一種の閉鎖を形成する。
【００５９】
図９の帯状体ＢＬ２に代えて図１０において両方の波光導体ＬＷ１＊，ＬＷｎ＊は完全に外被ＡＨ２の中へ一体化されている、即ちこれらは共通に波光導体Ｌ１〜Ｌｎと共に完全に外被のプラスチック材料の中に埋め込まれている。このようにして、その外被ＡＨ３に関して実質的に一様に形成されている波光導体帯状体ＢＬ３が構成されている。何故ならばその角部のファイバーもこの保護外被により囲まれているからである。
【００６０】
最後に図１１は、図１の帯状体Ｂ１１〜Ｂ１３ならびに図８〜図１０のＢＬ１〜ＢＬ３のための付加的なまたは独立の構成を示す：それぞれの波光導体帯状体は付加的な別の帯状体被覆（コーティング）により囲まれている。図１１においては例えば図８の帯状体ＢＬ１は別の帯状体コーティングＢＣにより完全に囲まれている。この場合、帯状体ＢＬ１は簡単化のためにほぼ長方形のブロックだけで示されている。見やすくするために帯状体コーティングならびに帯状体ＢＬ１の斜線も省略されている。付加的な帯状体コーティングとして例えば、既に設けられている帯状体外被ＡＨ１よりも１〜５倍小さい弾性係数を有する材料が選定される。好適にはこの付加的な帯状体コーティングは弾性係数５０〜５００Ｎ／ｍｍを有する。
【００６１】
そのため別の帯状体コーティングＢＣは、帯状体ＢＬ１の全体のまわりの付加的な軟かい−即ちバッファ−層を形成する。必要に応じて滑り剤添加物が、付加的な帯状体コーティングＢＣと帯状体ＢＬ１の外被との間に、または付加的な帯状体コーティングそのものの中に設けることができる。その目的は成層体の帯状体の間のまさつを低減させるためである。そのため成層体中の荷重がケーブル（屈曲の際のケーブル）の中の局所的な長さ超過／長さ不足の相殺により有利に低減される。図１１は２層の帯状体を示す。この帯状体の付加的な帯状体コーティング層ＢＣは、圧縮荷重を付加的に減衰する作用を有する。例えばこの付加的な帯状体コーティングＢＣの層の厚さは１０〜４０μｍであり、例えば２０〜３２０μｍに選定されている。次の値選定は実際に好適である：
ａ） 波光導体ＬＷ１＊，ＬＷ２＊の外径は０．２４５〜０．３００ｍｍ；
ｂ） 波光導体ＬＢ１〜ＬＢｎの外径は０．１８０〜０．２４５ｍｍ；
ｃ） 帯状体の全体の厚さ（付加的な帯状体コーティングＢＣを含む）λ（全体 の高さ）は０．２４５〜０３２ｍｍ。
【００６２】
図１４は例えば図１〜図１３に示されたそれぞれ同じ本発明の機種の１６の上下の層化された帯状体から成る長方形の帯状体成層体の場合の減衰比を示す。これは機械的圧縮力に対する同じ大きさの感応度のそれぞれの波光導体を有する従来の上下に層化された帯状体から成る１６段の帯状体成層体と比較したものである。図１４のダイヤグラムにはそれぞれ相対的減衰測定値α（ｄｂ／ｋｍ）が、第１の、両方の中央（即ち８番目と９番目の）のならびに最も下側および最も上側に位置する波光導体帯状体の最後のファイバー位置の場合に示されている。この場合、本発明により構成された帯状体成層体においていちばん上に位置する帯状体の場合の相対測定値は、それぞれ書き込まれた四角形により、いちばん下に位置する帯状体のための相対測定値は記入されていない空の四角形により示されている。従来の帯状体成層体のいちばん上に位置する帯状体の波光導体のための相対測定値は記入された円により、ならびにそのいちばん下に位置する帯状体のための測定値は空の記入されていない円により示されている。本発明による帯状体成層体の角部における減衰測定値は、即ちいちばん上ならびにいちばん下に位置する帯状体の１番目のならびに１６番のファイバー位置における減衰測定値は、従来のように構成された帯状体成層体の角部位置における波光導体の相対減衰測定値（α＝８．９；α＝４．０；α＝６．２；α＝５．３を比較のこと）を明らかに下回わる。少なくともいちばん上にならびにいちばん下に位置する帯状体の場合にそれぞれ外に、即ち少なくとも帯状体成層体の角部位置において、それぞれ波光導体が設けられており、この波光導体は、帯状体成層体ストラクチャのほとんど荷重の加わらない領域におけるよりも、生じ得る圧縮力に対して感応度が小さい。この構成により、帯状体成層体の角部位置における波光導体の伝送減衰の著しい低減化が達せられる。ケーブル直径が同じ場合は、標準帯状体を有する帯状体成層体に比較して係数２〜１２だけ減衰増加が低減される。さらに図１４の減衰ダイヤグラムは、中間のファイバー位置における波光導体のために、即ち本発明による帯状体成層体の場合のならびに従来の帯状体成層体の場合のそれぞれの帯状体における例えば８番目および９番目のファイバー位置における波光導体のために、ほぼ等しい伝送減衰を有することを明瞭に示す。この局所的ファイバー位置はストラクチャの内部でマイクロ屈曲なしに維持される。例えば図１〜図１１たとえば図８〜１１に示されている基本ストラクチャを有する帯状体成層体の本発明による構成により、図１の帯状体成層体の角部位置における波光導体に対しても、λ＝１５５０ｎｍの場合に０．３ｄＢ／ｋｍを下回わる減衰測定値が得られる。それぞれの帯状体における中間のファイバー位置は、より大きいマイクロ屈曲感応度を有する波光導体により占めることができる。何故ならばこれらは、生じ得る圧縮力をほとんど受けないからである。
【００６３】
生じえる押圧力に対して著しくけんろうなストラクチャは次の場合に得られる。即ち図１の成層体ストラクチャＳＴ１の全体の波光導体帯状体が同種の波光導体により、図１〜図１１たとえば図８〜図１の同じ実施例の帯状体により置き換えられている場合に得られる。そのため機械的に感応性のない波光導体は、仮想の長方形の外わく−これは内側に位置するその他の波光導体をほとんど荷重の加わらない領域において囲む−の上に位置する。
【００６４】
この種の、図１〜図１１に例えば図８〜図１１に示されている様に構成された帯状体は、波光導体技術における多種多様な適用に適する、例えば室ケーブル（図３）Ｕプロフィールケーブル（図１）または束ケーブル（図４）の室の中へ設置するために適する。
【図面の簡単な説明】
【図１】 本発明による第１の光ケーブルの横断面図である。
【図２】 図１による実施例の変形実施例である。
【図３】 図１による実施例の変形実施例である。
【図４】 図１による実施例の変形実施例である。
【図５】 マイクロ屈曲損失によるＭＡＣ値と減衰増加との関係を示すダイヤグラム図である。
【図６】 異なるＭＡＣ値の場合の減衰損失を限界波長に依存して示したダイヤグラム図である。
【図７】 帯状体成層体の上側、中間および下側帯状体である。
【図８】 図１により光ケーブルの場合の波光導体の第１の基本ストラクチャの横断面図である。
【図９】 図８の基本ストラクチャの第１の変形実施例である。
【図１０】 図８の基本ストラクチャの第２の変形実施例である。
【図１１】 図１に示された光ケーブル用の波光導体の別の基本ストラクチャを示す。
【図１２】 図１〜図１１によるストラクチャのための、機械的にほとんど感荷重を有しない波光導体の構成図である。
【図１３】 種々異なる厚さのコーティング層を有する波光導体におけるマイクロ屈曲によるＭＡＣ値と減衰増加との関係を示すダイヤグラムである。
【図１４】 図１〜図１１による基本ストラクチャを有する光ケーブルにおける帯状体成層体の上側、中間、下側の波光導体−帯状体における波光導体の減衰ダイヤグラムである。
【符号の説明】
ＯＣ１ 光ケーブル
ＣＡ１１〜ＣＡ１ｎ 室エレメント
ＣＥ１，ＣＥ２ 耐引っ張りエレメント
ＣＰ１ 支持体
ＳＴ１，ＳＴ４ ストラクチャ
Ｕ１１１〜Ｕ１１４，Ｅ１１２〜Ｅ１３３ 波光導体
ＡＸ１，ＡＸ２，ＡＸ４ 中性軸線
ＭＡ１，ＭＡ３ 外被
Ｕ４１１，Ｕ４１４，Ｕ４４１，Ｕ４４４ 波光導体
Ｂ４１〜Ｂ４４ 波光導体帯状体
ＣＡ３１〜ＣＡ３ｎ 切欠[0001]
[Industrial application fields]
  The present invention is an optical cable having a plurality of wave light conductors, the wave light conductors being provided in at least one group including a wave light conductor strip or a layered body composed of wave light conductor strips. The layered body composed of the body or the wave conductor strip is guided into the chamber element, and the wave conductors are subjected to different mechanical loads inside the layered body composed of the wave conductor strip or the wave conductor strip, Each of the wave light conductors of the wave light conductor band or the layered body made of the wave light conductor band relates to an optical cable having a plurality of wave light conductors having a MAC value formed from a quotient of each mode field diameter and effective wavelength limit.
[0002]
[Prior art]
  It is known to produce an optical cable having a remarkably large number of wave guides, in which case the wave guides are provided as a predetermined structure for each group. One possible configuration of this type of predetermined structure is, for example, an arrangement of wave conductor strips in the case of so-called room cables, for example inside a stratified body. An example of this type of structure is shown in European Patent A1492206, where the number of wave light guides is increased from the inside to the outside within a strip stratification that forms a group in order to obtain a remarkably large density. It increases as you go.
[0003]
  In the case of this type of group having a predetermined structure which is usually provided to run to the cable axis in a spiral, avoiding mechanical loads on the individual wave guides as they are, ie to the wave guides. In any case, it is not possible to take a position where a slight load is applied. This is because the wave guide is substantially mechanically coupled within the given structure at the aforementioned position. This is because mechanical loads of this kind (known under the name micro- or macro-bending) cause a substantially undesirably strong increase in damping.
[0004]
Problems to be Solved by the Invention
  An object of the present invention is to provide a configuration in which an excessive increase in attenuation based on a mechanical load of a wave light guide can be avoided as much as possible while maintaining a predetermined structure.
[0005]
[Means for Solving the Problems]
  This problem has been solved as follows:
  Wave light conductors having different micro-bending sensitivities are provided inside the wave light conductor band or the layered body composed of the wave light conductor bands,
  A wave conductor having a smaller MAC value is provided in one or more regions of the wave light conductor strip or a layered body comprising the wave light conductor strip where a large mechanical load appears;
  A wave light conductor having a micro bending sensitivity smaller than that of another wave light conductor in the wave light conductor band or in the layered body made of the wave light conductor band inside the wave light conductor band or inside the layered body made of the wave light conductor band. The wave light conductor has a larger distance from the neutral axis of the wave light conductor band or the layered body composed of the wave light conductor bands than the other wave light conductor in the wave light conductor band or the layered body composed of the wave light conductor band. And
  A wave guide with a smaller micro-bending sensitivity has a smaller MAC value than the other wave guides, where MAC is MAC = MFD / λ_ceffWhere MFD is the mode field diameter of the light guiding fiber and λ_ceffIs solved by being the effective wavelength limit,
  further,
  Wave light conductors having different micro-bending sensitivities are provided inside the wave light conductor band or the layered body composed of the wave light conductor bands,
  A wave conductor having a smaller MAC value is provided in one or more regions of the wave light conductor strip or a layered body of wave light conductor strips where a large mechanical load appears;
  The micro-bending sensitivity is smaller in the edge region of the wave conductor strip or in the corner region of the layered body of the wave conductor strip than the other wave light conductor in the wave conductor strip or the layered body composed of the wave conductor strips. A wave light conductor is provided,
  A wave guide with a smaller micro-bending sensitivity has a smaller MAC value than the other wave guides, where MAC is MAC = MFD / λ_ceffWhere MFD is the mode field diameter of the light guiding fiber and λ_ceffIs solved by being an effective limit wavelength.
[0006]
【The invention's effect】
  In the case of known known structures (for example in the case of strip stratification in a room cable), the same type of wave conductor is always used inside the structure, ie this kind of stratification. In contrast, the present invention starts from this principle of the same kind of wave light guide inside the structure. In this case, in the present invention, wave light guides having different sensitivities are used as follows. That is, where light mechanical loads occur significantly, first of all, wave guides that are designed for increased mechanical loads (eg micro-bending), ie have little micro-bending sensitivity to mechanical loads. Is installed or used. In other areas inside the structure, wave guides with higher sensitivity to mechanical loads can be used. This is because here the mechanical load of the wave guide is therefore less or no increase in attenuation is inherently caused. This is because wave optical conductors that are mechanically nearly micro-bending sensitive typically have higher transmission attenuation. This slight increase in transmission attenuation is several orders of magnitude smaller than the increase in attenuation due to mechanical loads that are too large for wave guides that are sensitive to micro-flexion to mechanical loads.
[0007]
  Various configurations of the present invention are shown in claims 3 and below.
[0008]
  Next, embodiments of the present invention will be described with reference to the drawings.
[0009]
【Example】
  The optical cable shown in FIG. 1 has a tensile-resistant element CE1 in the center. On top of this element is provided an extruded plastic layer CP1, for example made of polyethylene. On this plastic layer CP1, chamber elements CA11 and CA1n having a substantially U-shaped cross section are shown. During the twisting process, the chamber elements CA11 to CA1n are linearized so as to run spirally on the support CP1. Naturally, in the completed cable, the entire inner chamber between the exterior MA1 and the support CP1 is filled with n such chamber elements CA1-CAn. An exterior MA1 is provided on the outside. Within each chamber element, a group of wave light conductors (as shown in CA11) is provided with a predetermined structure. In this embodiment, in the case of the chamber element CA11, the structure ST1 is composed of layered bodies B11, B12, and B13 of wave light conductor strips each including four wave light conductors. Each of the predetermined structures ST1 forms a rectangular shape as a connection line to the wave light conductor located on the outer side.
[0010]
  As a result of the room element CA11 becoming more linear on the support CP1, the wave guide is subjected to different loads within the structure ST. In this case, substantially the following loads occur: a torsional load due to winding along the twisted axis (the center point of CE1) and a bending load due to the bent guide of the spiral path. These loads become larger as the extension in the radial direction and / or the circumferential direction of the structure ST1 including the wave light conductor increases. In this case, a special load is applied to the wave conductor located on the outermost side, because this wave conductor is the first from the (virtual) neutral axis AX1 that exists at the substantially intersection of the diagonal lines of the structure ST1 in terms of twisting and bending. Because they are separated.
[0011]
  The larger mechanical load of the wave guide (beyond a predetermined tolerance limit) will cause a significant increase in the transmission attenuation of the wave guide. For the purpose of avoiding this kind of degradation of the wave conductors in the specially loaded partial areas, for example the left and right corners on the outermost side of the structure ST1, there are mechanically particularly microscopic, shown here as black dots. Wave light conductors U111 and U114 having low bending sensitivity are provided. In this way, an excessively large attenuation increase due to the stranded process or as a result of the micro-refractive effect is substantially reduced.
[0012]
  Similarly, the wave light conductors subjected to the increased mechanical load also include the outermost wave light conductors U131 and U134 of the lowermost strip B13 of the layered body ST1. Therefore, also in this case, a wave light guide having a mechanically sensitive load that is significantly reduced is provided. On the other hand, the wave light conductors E132 and E133 of the wave light conductor strip B13, which are present on the innermost sides of both, are located closer to the neutral axis of the structure ST1 and therefore receive a mechanically smaller load. As a result, their attenuation due to mechanical loads is substantially not increased (eg during the stranded process).
[0013]
  The choice of wave guides, such as U111-U134, that should have less sensitivity inside the structure depends on the cable structure and the respective parameters of the stranded process. In this case, the length of one section that makes the individual structures more linear is processed such that an increased mechanical load is generated when the length of one section is shortened. Furthermore, the outer diameter of each structure is treated so that as the structure becomes larger (ie, the number of wave guides inside the structure increases), the mechanical load of the individual wave guides in the outer region also increases. How many of the wave guides in one structure are mechanically provided as light guides having a low micro-bending sensitivity, for example, U111-U134, depending on the given conditions and the arrangement inherent in each structure. Depends on characteristics. In addition to theoretical considerations in each case, the number and position of each wave-guide that is specially mechanically loaded inside the structure can also be easily determined by actual prototyping as follows. That is, in one cable embodiment, it is determined, for example, by measuring a wave light conductor that experiences an increase in attenuation that exceeds the tolerance limit as a result of the stranded process.
[0014]
  To clarify the above description, FIG. 2 is used. The optical cable OC2 shown here has an armor MA2, a tensile strength element and a plastic coating CP2 mounted thereon. The structure ST2 comprises three different wave conductor strips B21, B22 and B23 for the purpose of obtaining a significantly high transmission capacity. Each of these strips includes an increasing number of wave light guides when viewed from the outside to the inside. The entire inner chamber of the cable core is filled with a predetermined number of such structures. In the case of the present invention, to simplify the drawing, only the structure ST2 in which the chamber elements are included in the CA 21 is shown, while the other three structures that are similarly formed are shown only in outline. ing.
[0015]
  The outermost wave conductor strip B21 includes eight wave conductors. The three wave light conductors U211, U212 and 213 and U216, U217 and U218, which are located on the left- and right-outside respectively, are specially subjected to mechanical loads, and thus have an inner structure that makes them not particularly sensitive to mechanical loads. . On the other hand, the wave guides E214 and E215 provided near the center are not so far away from the neutral axis AX2 of the structure ST2 and therefore receive a mechanically smaller load. Therefore, it is not necessary for E214 and E215 to use wave guides that are characterized by a particularly small sensitive load relative to the mechanical load with respect to their damping characteristics.
[0016]
  In the case of the second wave guide strip B22 having a total of six wave guides, both the outer left and right wave guides are formed as sensitive wave guides U221, U222 and U225, U226 respectively. ing. On the other hand, both inner wave light conductors EP223 and E224 located closer to the neutral axis AX2 can have a greater sensitivity with respect to mechanical loads.
[0017]
  In the lowermost wave light conductor strip LB23 having a total of four wave light conductors, the wave light conductors U231 and U234 located on the outside of both are mechanically provided as wave light conductors having a low micro-bending sensitivity. On the other hand, the wave conductors E232 and E233 located on the inner side can have a greater sensitivity to mechanical loads. This is because E232 and E233 are located closer to the neutral axis AX2.
[0018]
  As shown in this embodiment of FIGS. 1 and 2, within the structure, the number and division of wave light conductors U111-U234, which are mechanically micro-flexible sensitive, are specific to each structure ST1 or ST2. Can be selected according to the micro-bending sensitivity. In this case, when the distance from the neutral axis AX1 or AX2 is increased, a wave light conductor having a mechanically low micro-bending sensitivity is used. On the other hand, in the core region, wave optical conductors E112 to E223 having a greater micro-bending sensitivity with respect to the attenuation characteristics with respect to the mechanical load are provided around the neutral axes AX1 to AX2.
[0019]
  In the case of the arrangement according to FIG. 3, the optical cable OC3 is provided with a larger plastic body CP3 provided with substantially rectangular chambers CA31 to CA3n, with the core CE3 having the tensile strength at the center as the center. An exterior MA3 is provided on the CP3, if necessary, under a cover (not shown) and an intermediate layer. In the rectangular cutouts CA31 to CA3n that run in a helical shape, a structure including a wave light conductor is provided, for example, in the form of a belt-like layered body. In the case of this embodiment, only one structure ST3 is shown. The structure and elements correspond to those of FIG. 1, that is, four wave light conductors U311 to U334 are provided at the corners, respectively, which have a particularly low microflexion sensitivity to mechanical loads.
[0020]
  FIG. 4 shows a stranded element OE. It has an outer protective sleeve SH, in which a structure ST4 consisting of a total of 16 wave conductors is accommodated. These 16 wave light conductors are divided into four wave light conductor strips B41-B44. Wave light conductors U411, U414, U441, and U444 arranged at the corners are formed as wave light conductors that have a particularly low micro-bending sensitivity to mechanical loads. On the other hand, the wave guide—located closer to the neutral axis AX4 of the structure ST4—shown as a white circle present further inside, has a greater microbending sensitivity.
[0021]
  The sensitivity of the fiber to microbending is shown in publications such as Bell "Sys. Tech. Journal 55, 1976, pp. 937-955. The measurement of the sensitivity is described in publications such as Bell" Sys. Tech. Journal 55, 1976, pages 937-955. The measurement is performed, for example, by a so-called “mesh wire test” shown in “International Wire and Cable Symposium” (IWCS) Proceedings 1989, page 450. The micro-bending sensitivity of the fiber or wave guide can be characterized by the MAC value shown, for example, in IWCS, Proceedings 1989, pages 704-709. Next, the MAC value is used for explanation of related matters.
[0022]
  The following formula applies:
[0023]
      MAC = MFD / λ_ceff
  As shown in this equation, when the mode field diameter MFD is made smaller, the bending sensitivity decreases (λ_ceff= Effective limit wavelength). A light guiding fiber having a first refraction value for the core region and a second predetermined refraction value for the sheath region typically has a MAC value that is about 7.5. If this MAC value 7.5 is reduced to, for example, 6.5 (for example by reducing the mode field diameter MFD), the microbending sensitivity is reduced by a factor greater than 2. As a result, this type of wave guide is subjected to an increased mechanical load. In this case, this does not cause an undesirably large increase in attenuation. This type of wave guide having a lower MAC value (ie, for example, 7.4, preferably 7.0, best even below 6.5) is the wave guide U111 of FIGS. Best for ~ U444. The difference between the MAC value of the wave light conductors (E112 to E223) having a high micro-flexibility sensitivity and the MAC value of the wave light conductors (U111 to U444) having a low micro-bending sensitivity should preferably be 0.2, for example It should have a value greater than 0.5 and optimally greater than 1.0. Said value is related to λ = 1300 nm.
[0024]
  For the purpose of obtaining the desired insensitivity of the wave guide, the design of the light guide fiber can be changed accordingly. For example, increasing the difference between the refractive index of the core of the light guiding fiber and the refractive index of the sheath improves the guiding properties of the fiber and thus makes it less sensitive to bending. Of course, this kind of improvement in the mechanical brazing of optical fibers usually results in a slight increase in attenuation, but this increase is a mechanically micro-bending sensitive light when the mechanical load increases. It is significantly smaller than the increase in attenuation of the guide fiber.
[0025]
  Next, the derivation of the relational expression explaining the above-mentioned phenomenon will be briefly described.
[0026]
  In FIG. 5, the micro refraction loss α depends on the MAC value, and a = 4 to 4.3 μm (a = core radius) and Δ (difference of normalized refractive index) = 0.333−0.0039% ( n₁= Refractive index of the core of the wave guide, n₂= Exterior refractive index).
[0027]
Δ = (n²(1) -n²(2)) / 2n²(1) (2)
V-parameter: (Structure parameter)
V = (2π / λ) α · n₁・ √2Δ (3)
Mode field diameter.
[0028]
[Expression 1]

[0029]
  Attenuation due to Rayleigh scattering
α_S= (0.685 + 66Δn) / λ⁴                          (5)
For the following refractive index, start with the following values:
Vc = 2.405
λc = λ_ceff+100 nm (λc = theoretical limit wavelength)
n₁= 1.451; where λ = 1300 nm
The following formula is obtained from (1) to (4).
[0030]
  Δ = (1 / 2π²) (ΛcVc / MAC · λ_ceff・ N₁) ... 0.65 + 1.619
    /(ΛcVc/λ)·+·2.879/(λcVc/λ)
  When the normalized refractive index difference Δ is converted into a refractive index difference Δn and the result is substituted into (5), λ shown in FIG._ceffAttenuation α as a function of_sIs obtained for different MAC values. Curve K1 is true for MAC = 6.5, curve K2 is MAC = 7, and curve K3 is true for MAC = 7.5.
[0031]
  As shown in FIG. 6, the kilometer attenuation (at 1300 nm) is still less than 0.4 dB / km even with MAC = 6.5. The attenuation is only about 5 · 10 ~ compared to the attenuation value when MAC = 7.5²Only dB / km increases. However, the microrefraction sensitivity is significantly reduced.
[0032]
  This type of fiber is therefore suitable, for example, for the location of cable structures where the fiber undergoes significantly greater microrefraction.
[0033]
  FIG. 7 shows the upper, middle and lower wave conductor L1-, consisting of a strip stratified body with ten fiber strips, provided in the cable of the U-profile shown in FIG. The attenuation value α of L12 is shown.
[0034]
  The broken line indicates the attenuation value of the fiber strip in the state where no load is applied. That is, all the wave guides L1-L12 have the same attenuation of 0.2 dB / km when the wavelength is 1550 nm. When fibers with high microbending sensitivity are used, the attenuation for both wave conductors on the outermost side of the outer band is significantly increased in the case of the aforementioned loads, for example in the case of stranded wire itself or in the internal temperature test of the cable. , At the values indicated by white circles EL1 and EL12. That is, the attenuation increase has a value of about 1.0 dB / km. In this case, the MAC value 8.2 is defined. On the other hand, when a fiber with a low microbend sensitivity MAC value of 6.8 is used for both outermost waveguides L1 and L12, the increase in attenuation in both outer waveguides is markedly small. Only the values indicated by UL1 (about 0.33 dB / km) and point UL12 (about 0.45 dB / km) are reached.
[0035]
  Therefore, by using a wave light guide with little micro-bending sensitivity in the critical region of the structure according to the present invention, a significant improvement in the overall properties of the structure is achieved. Specifically, the following points are improved:
  An overall smaller attenuation value is obtained under the maintenance of this structure.
[0036]
  For a given attenuation value, disadvantageous processing parameters (larger bend, smaller section length) are acceptable.
[0037]
  If the processing parameters and attenuation do not change, more wave guides can be installed inside the structure.
[0038]
  Rather than only six wave guides inside one strip inside one stratification, but eight wave guide stratifications inside one strip without exceeding the allowed error value. ,realizable.
[0039]
  It is also possible to construct all wave guides with only a small bending sensitivity within one given structure, ie a MAC value of 7.4, preferably 7.0, and even 6.5 if necessary It is also possible to configure all wave guides with MAC values lower than
[0040]
  The actual given conditions, such as the dimension selection to be maintained, are not necessarily considered as they are when a structure having a wave light guide with a low micro-bending sensitivity is mechanically constructed in the region that receives the strongest load inside the structure. It's okay. Therefore, another configuration object of the present invention is to provide a means for easily constructing a predetermined structure having wave guides with different micro-bending sensitivities, under sufficient consideration of actual given conditions. is there. This problem is solved as follows by the first solving means of this modified embodiment. That is, wave guides in higher mechanical load areas have been solved by making the thickness of the primary coating layer greater than wave guides in lower mechanical load areas.
[0041]
  Increasing the thickness of the wave guide first covering sleeve (primary coating) in the region of higher mechanical loads, respectively, can cause unacceptably high attenuation increases in the transmission characteristics of the wave guide. -And / or the effect of macro bending (so-called "micro- or macro bending") is hardly affected. This is because an increase in the thickness of the primary coating advantageously provides an additional damping action, for example on the mechanical loads that can be generated, for example compression loads. In addition, this type of wave guide allows various deformable structure configurations that are very easily adapted to the actual given conditions. This is because, by adjusting the thickness of the primary coating of each wave guide as desired, for example, the predetermined space state of the structure, the value selection data, the maximum allowable compressive force on each wave guide, etc. This is because the structure can be considered in an extremely simple and advantageous manner.
[0042]
  According to the second solving means of the modified embodiment, the above-mentioned problem is solved as follows. That is, the wave guide in each region of higher mechanical load is solved by having a softer material for its first coating than the wave guide in the region of lower mechanical load.
[0043]
  This advantageous configuration avoids unacceptably high transmission attenuation, even for wave guides at higher mechanical loads within the structure. For the same outer diameter, the more heavily loaded wave guide with softer material for the primary coating is better cushioned, i.e. mechanically, than the wave guide with less load. Attenuated. In this way, an optimized structure configuration adapted to various given conditions is possible.
[0044]
  A greater primary coating thickness (primary coating) and at the same time than for a mechanically lightly loaded wave light conductor primary coating due to the more heavily loaded wave light primary coating It is particularly advantageous to provide a softer material. This combined configuration significantly simplifies the structure to meet various given conditions such as value selection data, mechanical minimum load (brazing), allowable pass attenuation for each individual wave light guide, etc. Composed.
[0045]
  1 is substantially supported by the four fibers U111, U114, U131, U134 at the corners in the chamber space. For the purpose of this type of attenuation increase, for example, temperature cycling, bending- or lateral pressure tests can be carried out if necessary, i.e. the corner fibers are the most sensitive in the stratification.
[0046]
  The desired insensitivity of the wave light conductor of the structure—for example in their four corner areas—is obtained as follows: design of the coating of the light guiding fiber at the point of higher mechanical load (coating design) Is obtained by being deformed compared to that of the light guiding fiber in the region of lower mechanical load. FIG. 12 shows the structure of the wave light guide LW1 *. This can be used, for example, for wave light guides U111 to U134 with a low mechanical microbending sensitivity in structure ST1 of FIG. The wave light guide LW1 * in FIG. 12 has a light guiding glass core CO at the center. The CO is surrounded by an exterior glass (“coating”) CL. As a result, a light guide fiber having an outer diameter DF is formed. At least one primary inner plastic coating (primary coating) PC is deposited on the light guiding fiber. For this primary coating PC, for example, a soft material such as urethane acrylate having an elastic modulus of 0.5 to 2.5 MPa is selected. This primary coating PC is further covered by at least one secondary, further external coating (secondary coating). For this secondary coating SC, a material harder than that for the primary coating, such as SC, urethane acrylate or silicon acrylate epoxy acrylate-elastic modulus 500-1500 MPa-substantially damages the outer surface of the primary coating PC. In order to avoid this problem, it is selected for the purpose of enabling further processing without any problem of the light guiding fiber.
[0047]
  In order to make the wave guides at higher mechanical loads, eg U111 to U134 in FIG. 1, mechanically less sensitive to the pressure that can be used within the structure ST1, the coating of the wave guides is as follows: It is formed as follows. That is, the coating is formed such that each has a primary coating having a greater layer thickness than wave guides, such as E112-E133, at low mechanical loads. The basis for this is that, as shown in “International Wired Cable Symposium Proceedings” (IWCS), 1993, pp. 389-390, the primary coating PC affects the microbending sensitivity of the wave guide. It is. For example, the wave guides U111 to U134 in the region of higher mechanical pressure load are 1.5 to 4 times, for example 2-3, respectively, than the wave guides such as E112 to E133 in FIG. It has a layer thickness of its primary coating PC that is twice as large. A layer thickness of 20 to 50 μm, for example 30 to 40 μm, is preferably selected for the primary coating PC of a wave light conductor which is mechanically less sensitive. For example, increasing the thickness of the soft primary coating PC increases its cushioning or buffering action. As a result, the pressure load on each light guiding fiber that can act is attenuated to form an overall stiffer wave light guide.
[0048]
  The light guide fiber of the wave light guide LW1 * of FIG. 12 provided with the primary coating PC is 1.1 to more than the wave light guide having a mechanically high micro bending sensitivity such as E112 to E133 of FIG. The outer diameter DPC is 1.5 times larger, for example 1.2 to 1.4 times larger. For example, the outer diameter DPC is selected to be 165 to 250 μm, for example 170 to 210 μm. Is the secondary coating SC in the case of the wave conductors U111 to U134 of FIG. 1 with a smaller microbending sensitivity approximately equal to the secondary coating of the wave conductors E112 to E133 of FIG. Or 1.1 to 2 times greater layer thickness, respectively. The layer thickness for the secondary coating SC is preferably selected from 10 to 40 μm, for example 20 to 30 μm. For this reason, the wave light conductor LW1 * which is mechanically brittle with respect to the compressive load is 1.2 to 1.8 times, for example 1.2 times, the wave light conductors E112 to E133 having a high micro-bending sensitivity in FIG. It has an overall outer diameter that is ~ 1.5 times larger. For example, the overall outer diameter DLW is selected to be 200 to 300 μm, for example 200 to 250 μm.
[0049]
  In order to explain the influence of the primary coating PC on the microbending sensitivity of each wave guide, the following table shows, for example, five different coating types T1-T5 of the wave guide.
[0050]
  These are subjected to the so-called “mesh wire test”, for example as shown in “International Wired Cable Symposium (IWCS) Proceedings, 1989, page 450. Each of the light guide types T1 to T5 is individually and individually The associated elastic modulus is shown for outer diameter DLW, light guiding fiber diameter DF, outer diameter DPC, light guiding fiber coated with primary coating PC, and primary coating PC and secondary coating SC. .
[0051]
    Table 1
  DLW DPC DF coating Elastic modulus of PC SC
  [μm] [μm] [μm] Model [MPa] [MPa]
   180 150 125 T1 1.6 1530
   200 150 125 T2 1.6 1530
   200 165 125 T3 1.6 1530
   245 205 125 T4 2.6 690
   245 190 125 T5 1.6 580
  In FIG. 13, for example, for five different coated wave conductors T1 to T5, the micro bending loss (attenuation loss) α * dB / kg compressive load depends on the so-called MAC value, respectively, and the MAC region at a wavelength of 1550 nm. For example, it is shown over 6.5-8.5. The MAC value characterizes the micro-sensitivity of the fiber or wave guide, as shown in IWCS, Proceedings 1988, pages 704-709. Next, the MAC value is used for explanation of related matters. In this case, the following formula applies:
              MAC = MFD / λ_ceff
As shown in this equation, the bending sensitivity decreases as the mode field diameter MFD of each wave light conductor decreases. The measurement line for the coating type T1 of Table 1 indicated by T1 * in FIG. 13 shows the attenuation ratio based on the micro bending loss in the case of the current monomode wave guide depending on the MAC value. Compared to the primary coating type T1, in the case of the secondary coating type T2, the secondary coating is increased by about 20 μm. This gives rise to a measurement line T2 * which is slightly below the measurement line T1 in the attenuation diagram of FIG. On the other hand, a significant reduction or reduction in transmission attenuation is achieved by increasing the thickness of the primary coating layer. This means, for example, the coating type T3—its measurement line T3 * runs below and substantially parallel to the measurement line T2 * at an interval of about 0.05 dB / kg (1 measurement unit). FIG. 13 further shows a measurement straight line T4 * in the case of the coating type of Table 1. This straight line runs significantly below the measurement curve T3 * and with a slope smaller than T3 *. The coating type T4 is characterized by a larger layer thickness (DPC-DF = 80 μm) of the primary coating than the coating type T3. At the same time, in the case of the secondary coating PC, a material having a smaller elastic modulus, for example less than half, is selected in this embodiment. In the case of this coating T4 design, a further reduction in attenuation loss is achieved. This is indicated by the measurement line T4 * traveling at a smaller slope than the measurement curve T3 * in the MAC region of 6.5 to 8.5. In the case of the coating type T5, the wave guide can finally be made approximately independent of the outer compressive load in the MAC value region 6.5-8.5. This can be achieved, for example, by reducing the elastic modulus of the primary coating PC from that of type T4. This is shown in the measurement curve T5 * traveling in an approximately constant manner below T4 *.
[0052]
  In the case of a wave light conductor positioned at the location of higher mechanical loads, for example pressing forces, in addition or not dependent on the increase in the thickness of the primary coating layer, for example U111- In the case of U134, these are made more micro-bending sensitive to pressure, i.e., more crawled, if necessary as follows. That is, for the primary coating PC, a softer material is selected than for wave light conductors in the range of smaller mechanical loads within the structure ST1 of FIG. In other words, it is possible to make the microbending sensitivity more sensitive to the pressure, that is, to make it more funky. Therefore, advantageously, wave guides such as U111 to U134 of FIG. 1 in the region of higher mechanical load have as little elastic modulus as possible than wave guides in the region of lower mechanical load. For example, because of the primary coating PC of the wave conductor of FIG. 1 that is heavily loaded, it is 1 to 5 times, for example, 1-2, than the material for the wave conductors E112 to E133 of FIG. .5 times softer material is selected. Due to the primary coating of the wave conductors U111 to U134, which are particularly advantageously loaded in FIG. 1, the elastic modulus is, for example, 1 to 2.5 times smaller than the elastic modulus for the wave conductor in the region of smaller loads. Is selected. Preferably, the lighter light guides U111 to U134 of FIG. 1 have an elastic modulus of 0.5 to 3, for example 1 to 2 MPa. In addition to or without depending on this configuration, the wave light guide in the region of higher pressure load can be made more sensitive to pressure if necessary as follows. That is, by selecting a softer material for the secondary coating than the material of the light guide subjected to a smaller load, it can be made more sensitive to pressure. The elastic modulus for the secondary coating of the lighter wave conductors U111 to U134 is preferably 1.0-2. 2 higher than that of the wave conductors E112 to E113, which are mechanically more sensitive to microbending. 5 times, for example, 1.0 to 2.0 times larger is selected. For example, secondary coatings for wave light conductors U111 to U134 that are mechanically more stable to pressure have an elastic modulus of 500 to 1600 MPa, for example 800 to 1500 MPa. The secondary coating therefore advantageously acts as a protective layer. Therefore, the external force can be transmitted from the secondary coating SC to the surface of the inner coating (primary coating) PC.
[0053]
  Therefore, the influence of the elastic modulus of the secondary coating is substantially negligible compared to the influence of the primary coating.
[0054]
  Therefore, the wave guide having the coating types T3 to T5 in Table 1 is smaller in the MAC value region of about 6.5 to 8.5 than the wave guide whose value is selected as usual so as to correspond to the coating type T1. Has micro bending loss. For this reason, a modified wave light guide of this kind is positioned at the location of the structure ST1 in FIG. In the embodiment of FIG. 1, this position is, for example, the position of the four corners in the belt-like layered body. However, particularly in the case of all the strips B11, B12 and B13, this type of pressure-sensitive wave light conductor can also be provided at each corner position in the strip-like layered body of FIG.
[0055]
  FIG. 8 shows a wave conductor strip BL1 as a basic unit of the structure ST1 of FIG. This strip-like body BL1 occupies only the place of B13 located at the bottom of FIG. 1 and / or the place of the strip-like body B11 located at the top of the strip-like layered body (structure ST1) of FIG. On the other hand, the other strips attached in the middle can be strips according to the conventional design each having the same kind of wave guide. However, as an alternative, all the strips in the layered body ST1 of FIG. 1 can be constructed in the form of BL1, ie in the same form. This alternative form has the advantage that an integral multiple splice device can be used.
[0056]
  The strip BL1 is composed of a substantially rectangular elongated plastic outer coating AH1 and a wave guide standard strip GB having at least one additional wave guide LW1 *, LWn *, respectively. Each of the latter is individually abutted against the outer cover AH1 using the connecting means VM in the longitudinal direction on the outer short side of the standard strip GB. Therefore, the n wave light conductors LW1 to LWn are embedded in the outer sheath AH1 of the standard belt GB and the side surfaces are limited by the two separate wave light conductors LW1 * and LWn *, and as a result, more than the standard belt GB. A wide belt-like body BL1 is formed. In this case, the wave conductors LW1 to LWn are accommodated in the center of the jacket AH1 along a virtual straight connection line. On the other hand, both wave conductors LW1 *, LWn * follow on both sides of this virtual connection line without an outer protective covering. The separate additional wave conductors LW1 *, LWn * are shown in FIG. 8 with a larger diameter than the wave conductors LW1-LWn of the standard strip GB. This means the following. That is, in FIG. 8, this kind of wave light conductors LW1 * and LWn * is provided for the wave light conductors U111 to U134 as described above. Advantageously, both of these wave conductors LW1 *, LWn * have a layer thickness of their primary coating that is greater than the wave conductors LW1 to LWn that are subjected to a small compressive load because they are located on the inside (for example the coating of Table 1). Wave conductor corresponding to type T3). Of course, all the other wave conductor types mentioned above (different refractive indices for the core and outer period, ie different MAC values) and wave conductors LW1 *, LWn * which are less sensitive to micro-bendings in the possible pressing forces, for example table 1 Coating designs for wave guides corresponding to the coating types T3, T4 and T5 can also be used. As the connection means VM for the wave light conductors LW1 *, LWn *, for example, an adhesive, a normal strip coating or other adhesive means can be selected.
[0057]
  In FIG. 8, the wave conductors LW1 * and LWn * that limit the standard band GB on the side face act in the form of side edge protection for the wave conductors LW1 to LWn located inside. For this reason, they are provided in the belt-like body BL1 where the strongest possible pressing force is received, that is, at the end of the belt-like body BL1. Only the wave conductors LW1 * and LWn * provided on the outermost sides of both of the strips BL1 in FIG. 1 each have an outer coating of the primary coating, and nevertheless, as a whole, within the outer coating AH1. Approximately the same amount of strip is maintained as that of a standard strip with n + 2 similar wave light guides. In this way, a remarkably compact strip BL1 having two different types of wave conductors is formed. Small pressure-stable wave light conductors LW1 to LWn in the inner region defined by the envelope AH1, and at least two pressures in the outer side of the standard strip GB which are subjected to possible loads and opposite to each other. Waveguides LW1 * and LWn * that are even more stable. This strip BL1 is therefore characterized by a remarkably high concentration density and by a remarkably simple production. Furthermore, a uniform fiber position in the strip is advantageously possible during manufacture.
[0058]
  In the case of the wave conductor strip BL2 of FIG. 9, the difference from the strip BL1 of FIG. 8 is that both wave conductors LW1 and LWn * are integrated on one side into the corner portion of the short side of the jacket AH1, respectively. There is in point. The wave conductors LW1 * and LW2 * form a rounded short side whose outer contour is for the strip BL2. (Parts taken directly from FIG. 8 are indicated by the same reference symbols in FIG. 9). The wave conductors LW1 * and LW2 * have an outer diameter corresponding to the thickness of the strip. The wave guide thus forms a kind of closure for the short side of the jacket AH1.
[0059]
  In FIG. 10, instead of the strip BL2 in FIG. 9, both wave guides LW1 *, LWn * are completely integrated into the jacket AH2, ie they are completely external together with the wave guides L1-Ln. Embedded in the plastic material. In this manner, the wave light conductor strip BL3 is formed substantially uniformly with respect to the outer cover AH3. This is because the corner fiber is also surrounded by this protective jacket.
[0060]
  Finally, FIG. 11 shows an additional or independent configuration for the strips B11-B13 of FIG. 1 and BL1-BL3 of FIGS. 8-10: each wave guide strip is an additional separate strip. Surrounded by body coating. In FIG. 11, for example, the strip BL1 of FIG. 8 is completely surrounded by another strip coating BC. In this case, the belt-like body BL1 is shown only by a substantially rectangular block for simplicity. For ease of viewing, the belt-like body coating and the oblique line of the belt-like body BL1 are also omitted. For example, a material having an elastic modulus that is 1 to 5 times smaller than that of the already provided strip-shaped casing AH1 is selected as the additional strip-shaped coating. Preferably this additional strip coating has an elastic modulus of 50 to 500 N / mm.
[0061]
  Thus, another strip coating BC forms an additional soft-or buffer layer around the entire strip BL1. If desired, a slip additive can be provided between the additional strip coating BC and the jacket of the strip BL1 or in the additional strip coating itself. The purpose is to reduce glare between the strips of the stratified body. Therefore, the load in the stratification is advantageously reduced by local over / under length cancellation in the cable (cable during bending). FIG. 11 shows a two-layer strip. The additional band coating layer BC of the band has an action of additionally attenuating the compressive load. For example, the thickness of this additional strip coating BC is 10 to 40 μm, for example 20 to 320 μm. The following value selection is actually suitable:
a) The outer diameter of the wave light conductors LW1 * and LW2 * is 0.245 to 0.300 mm;
b) Wave conductors LB1 to LBn have an outer diameter of 0.180 to 0.245 mm;
c) Overall thickness of the strip (including additional strip coating BC) λ (overall height) is 0.245-032 mm.
[0062]
  FIG. 14 shows the attenuation ratio in the case of a rectangular strip-like layered body composed of 16 upper and lower layered strips of the same model of the present invention shown in FIGS. 1 to 13, for example. This is in comparison to a conventional 16-layer strip-layered body consisting of top and bottom layered strips with respective wave light guides of the same magnitude sensitivity to mechanical compression force. Each of the diagrams of FIG. 14 has a relative attenuation measurement α (db / km) in the first, both middle (ie, eighth and ninth) and lowermost and uppermost wave guide bands. Shown for the last fiber position of the body. In this case, the relative measurement value in the case of the strip located at the top in the strip stratified body constituted according to the present invention is the relative measurement value for the strip located at the bottom by the written quadrangle, respectively. It is indicated by an empty square that is not filled in. Relative measurements for the strip lightwave conductor located on the top of the conventional strip stratification are indicated by the circles filled in, and the measurements for the strip located below it are filled in empty. Indicated by no circle. The attenuation measurements at the corners of the strip stratification according to the present invention, i.e. the attenuation measurements at the first and 16th fiber positions of the strip located at the top and bottom, were constructed as before. Clearly below the measured relative attenuation of the wave conductor at the corner of the strip stratified body (α = 8.9; α = 4.0; α = 6.2; α = 5.3, compare) Worse. In the case of at least the uppermost band and the lowermost band-like body, wave light conductors are respectively provided outside, that is, at least at the corners of the band-like body layered body. Is less sensitive to the compressive force that can occur than in areas where little load is applied. With this configuration, it is possible to achieve a significant reduction in the transmission attenuation of the wave light conductor at the corner position of the strip-shaped body laminate. When the cable diameter is the same, the increase in attenuation is reduced by a factor of 2-12 compared to a strip stratified body having a standard strip. Furthermore, the attenuation diagram of FIG. 14 shows, for example, the 8th and 9th for the wave conductors in the intermediate fiber positions, ie in the case of the strip stratification according to the invention and in the case of the conventional strip stratification, respectively. It is clearly shown that it has approximately equal transmission attenuation due to the wave conductor at the second fiber position. This local fiber position is maintained within the structure without microbending. For example, by the configuration according to the present invention of the strip-shaped body laminate having the basic structure shown in FIGS. 1 to 11, for example, FIGS. 8 to 11, the wave light conductor at the corner position of the strip-shaped body laminated body of FIG. Attenuation measurements below 0.3 dB / km are obtained for λ = 1550 nm. The middle fiber position in each strip can be occupied by a wave light conductor with greater microbending sensitivity. This is because they are hardly subjected to the compressive force that can occur.
[0063]
  A strikingly stubborn structure against the possible pressing force is obtained in the following cases. That is, it is obtained when the entire wave light conductor strip of the layered structure ST1 of FIG. 1 is replaced by the same kind of wave light conductor with the belt of the same embodiment of FIGS. 1 to 11, for example, FIGS. Therefore, a wave light guide that is not mechanically sensitive lies on the outer edge of a virtual rectangle, which surrounds the other wave light guide located inside in a region where little load is applied.
[0064]
  A strip of this kind, configured as shown in FIGS. 1-11 for example in FIGS. 8-11, is suitable for a wide variety of applications in wave-guide technology, for example a room cable (FIG. 3) U profile. Suitable for installation into the room of cable (Fig. 1) or bundle cable (Fig. 4).
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a first optical cable according to the present invention.
FIG. 2 is a variant embodiment of the embodiment according to FIG.
FIG. 3 is a variant embodiment of the embodiment according to FIG.
FIG. 4 is a variant embodiment of the embodiment according to FIG.
FIG. 5 is a diagram showing a relationship between a MAC value due to micro bending loss and an increase in attenuation.
FIG. 6 is a diagram showing attenuation loss depending on a limit wavelength in the case of different MAC values.
FIG. 7 shows the upper, middle and lower band-like bodies of the belt-like body layered body.
FIG. 8 is a cross-sectional view of a first basic structure of a wave light conductor in the case of an optical cable according to FIG.
9 is a first modified example of the basic structure of FIG.
10 is a second modified embodiment of the basic structure of FIG.
FIG. 11 shows another basic structure of the wave light guide for the optical cable shown in FIG. 1;
FIG. 12 is a block diagram of a wave light conductor that has little mechanical load sensitivity for the structure according to FIGS.
FIG. 13 is a diagram showing the relationship between the MAC value due to micro-bending and the attenuation increase in a wave light guide having coating layers with different thicknesses.
FIG. 14 is an attenuation diagram of a wave light conductor in the upper, middle, and lower wave light conductors-bands of the belt-like layered body in the optical cable having the basic structure shown in FIGS. 1 to 11;
[Explanation of symbols]
      OC1 optical cable
      CA11 to CA1n chamber elements
      CE1, CE2 Tensile element
      CP1 support
      ST1, ST4 structure
      U111-U114, E112-E133 Wave light guide
      AX1, AX2, AX4 neutral axis
      MA1, MA3 jacket
      U411, U414, U441, U444 Wave light conductor
      B41-B44 Wave light conductor strip
      CA31-CA3n Notch

Claims (29)

An optical cable having a plurality of wave light guides, the wave light conductor is provided in at least one group including a stratified body consisting of a wave optical conductor strip or wave light conductor strip,
The wave conductor strip or the layered body composed of the wave conductor strips is led into the chamber element, and the wave conductors are mechanical loads different from each other inside the wave conductor strip or the layered body composed of the wave conductor strips. Have received
Each of the wave light conductor strips or the layered wave light conductors of the wave light conductor bands has a MAC value formed from the quotient of the respective mode field diameter and effective wavelength limit, and has a plurality of wave light guides. Oite to cable,
The wave light conductor having different micro-bending sensitivities is provided inside the wave light conductor band or a layered body composed of the wave light conductor band,
A wave conductor having a smaller MAC value is provided in one or more regions of the wave light conductor strip or a layered body comprising the wave light conductor strip where a large mechanical load appears ;
A wave light conductor having a micro bending sensitivity smaller than that of another wave light conductor in the wave light conductor band or in the layered body made of the wave light conductor band inside the wave light conductor band or inside the layered body made of the wave light conductor band. The wave light conductor has a larger distance from the neutral axis of the wave light conductor band or the layered body composed of the wave light conductor band than another wave light conductor in the wave light conductor band or the layered body composed of the wave light conductor band. Yes, and
A wave guide with a smaller micro-bending sensitivity has a smaller MAC value than the other wave _guides , where MAC is given by MAC = MFD / λ _ceff , where MFD is the mode field of the light guiding fiber in diameter, lambda _ceff is characterized by an effective threshold wavelength, light cable having a plurality of wave light guides. An optical cable having a plurality of wave light conductors, the wave light conductors being provided in at least one group including a wave light conductor strip or a layered body composed of wave light conductor strips,
The wave conductor strip or the layered body composed of the wave conductor strips is led into the chamber element, and the wave conductors are mechanical loads different from each other inside the wave conductor strip or the layered body composed of the wave conductor strips. Have received
An optical cable having a plurality of wave light conductors, each of the wave light conductor strips or a layered wave light conductor formed of the wave light conductor belts having a MAC value formed from a quotient of each mode field diameter and effective limit wavelength. In
The wave light conductor having different micro-bending sensitivities is provided inside the wave light conductor band or a layered body composed of the wave light conductor band,
A wave conductor having a smaller MAC value is provided in one or more regions of the wave light conductor strip or a layered body comprising the wave light conductor strip where a large mechanical load appears;
The micro-bending sensitivity is smaller in the edge region of the wave conductor strip or in the corner region of the layered body of the wave conductor strip than the other wave light conductor in the wave conductor strip or the layered body composed of the wave conductor strips. A wave light conductor is provided,
A wave guide with a smaller micro-bending sensitivity has a smaller MAC value than the other wave _guides , where MAC is given by MAC = MFD / λ _ceff , where MFD is the mode field of the light guiding fiber in diameter, lambda _ceff is characterized by an effective threshold wavelength, light cable having a plurality of wave light guides. For the Namikoshirube having a smaller micro bending sensitivity, lambda = in the case of 1300 nm, MAC values are selected such Waru fall below the 7.4, lambda is the operation of the light used in Namiko conductor The optical cable according to claim 1 , wherein the optical cable has a wavelength. Micro bending sensitivity of the larger Namikoshirube body and the micro bending sensitivity small Namikoshirube bodies, in their MAC values differ from each other by at least 0.5, any one optical cable as claimed in claims 1 to 3. Small Namikoshirube body having large Namikoshirube body and the micro bending sensitivity of micro-bending sensitivities in their MAC value, at least by different, any one optical cable as claimed in claims 1 to 3. Structure (ST1) is provided inside the chamber element of U-shaped (CA1), said element being more SENKA with other this kind element, any one of claims 1 to 5 Optical cable. The optical cable according to any one of claims 1 to 6 , wherein the structure (ST2) is accommodated in a chamber element (CA21) having a substantially trapezoidal cross section. The optical cable according to any one of claims 1 to 6 , wherein the structure is provided inside a profile body (CP3) provided with chamber-shaped recesses (CA31 to CA3n). The structure (ST4) is housed in a closed protective jacket (SH), and a plurality of such stranded elements are more linearized into one cable core. The optical cable according to any one of 6 to 6 . 10. An optical cable according to any one of claims 1 to 9 , wherein all wave light guides of the structure have a MAC value below 7.4. 10. An optical cable according to any one of claims 1 to 9 , wherein all the wave guides of the structure have a MAC value below 7.0. Wave layer conductors (U111 to U134) in the higher mechanical load region, respectively, have a greater layer thickness of their primary coating (PC) than wave light guides (E112 to E133) in the lower mechanical load region. and that, any one optical cable as claimed in claims 1 to 11 which has a of. Waveguides (U111 to U134) in the higher mechanical load region are 1.5 to 4.5 times the primary coating than waveguides (E111 to E133) in the lower mechanical load region The optical cable according to claim 12 , having a thickness of Waveguides (U111-U134) in the higher mechanical load region have a layer thickness two to three times that of the primary coating than waveguides (E111-E133) in the lower mechanical load region. The optical cable according to claim 12 . 15. Optical cable according to claim 13 or 14 , wherein the primary coating of wave light conductors (U111 to U134) in the region of higher mechanical loads has a layer thickness of 0.02 to 0.05 mm. 15. Optical cable according to claim 13 or 14 , wherein the primary coating of the wave light guide (U111 to U134) in the region of higher mechanical loads has a layer thickness of 0.03 to 0.04 mm. Waveguides (U111-U134) in the higher mechanical load region are each less elastic modulus for their primary coating (PC) than waveguides (E111-E133) in the lower mechanical load region with a material having a any one optical cable as claimed in claims 1 to 16. For wave guides (U111-U134) in the region of higher mechanical load, 1 to 1 for its primary coating (PC) than for wave guides (E112-E133) in the region of low mechanical load. 18. An optical cable according to claim 17 , wherein a material having a modulus of elasticity 5 times smaller is provided. For wave guides (U111-U134) in the region of higher mechanical load, 1 to 1 for its primary coating (PC) than for wave guides (E112-E133) in the region of low mechanical load. 18. An optical cable according to claim 17 , wherein a material having an elastic modulus 2.5 times smaller is provided. The urethane acrylate having an elastic modulus of 0.5 to 2.5 MPa is selected as the material for the primary coating (PC) of the wave guide (U111 to U134) in the region of higher mechanical loads. optical cable according one of of up to 17-19. Wave light conductors (for example, U111, E112, E113, U114) are provided in the wave light conductor-band-shaped body (for example, B11) forming the structure, and wave light conductors (for example, outside the band-shaped structure (for example, B11)) The optical cable according to any one of claims 1 to 20 , wherein U111, U114) has a smaller microbending sensitivity than a wave light conductor (for example, E112, E113) located inside thereof. 21. The optical cable according to claim 20 , wherein the plurality of wave conductor strips are grouped to form a layered body forming the structure (ST1). The wave light conductor-band-like body (for example, BL1) is constituted by the standard band-like body (GB) having the following wave light conductors (LW1 to LWn), that is, positioned outside on the narrow side of the band-like body and inside. In addition, at least one wave light conductor (for example, LW1 *, LWn *) is additionally provided with a micro-bending sensitivity smaller than the wave light conductors (LW1 to LWn) of the standard band (GB). The optical cable according to claim 20 or 21 , wherein the optical cable is constituted by a standard strip having a wave light conductor. 23. The optical cable according to claim 22 , wherein wave optical conductors (LW1 *, LWn *) additionally provided on the side surfaces are connected by connecting means (VM), respectively. The wave light guides (LW1 *, LW2 *) having a smaller micro-bending sensitivity occupy corner positions in the strips (BL2), respectively, in which the jacket (AH1) is closed outwards. The optical cable according to 20 or 21 . Smaller micro bending sensitivity wave light guide (LW1 *, LW2 *) is embedded in a corner position of the strip (BL3) inside the envelope (AH3) of the strip, according to claim 20 or 21 The optical cable described. 26. Optical cable according to any one of claims 20 to 25 , wherein each wave conductor-band (e.g. BL1, BL2 or BL3) is surrounded by an additional protective layer (BC). The optical cable according to any one of claims 1 to 27 , wherein the layered body forming the structure (ST1) is composed of the same kind of wave conductor strips (BL1, BL2, BL3) according to claims 20 to 26. . 27. The stratified body forming the structure (ST1) at the bottom and on the top, having a wave conductor strip (BL1, BL2, BL3) according to claims 20 to 26, according to any one of claims 12 to 26 . Optical cable.

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