200416420 玖、發明說明： (一） 發明所屬之技術領域 本發明係有關於連接兩條光纖之構造。 (二） 先前技術 在以往，連接兩條光纖之構造中，大致分爲兩種構造而 爲人所知。 一種，係將兩條光纖之前端彼此在核心聚集於相同軸心 之狀態下進行融合之構造。另一種，係將兩條光纖以不融 合而分別將各核心之前端彼此接觸之狀態進行連接之構 造。後者更具有具體之構造，例如特公平4-693 69號公報 所記載般，由分別固定兩條光纖之前端部之兩個套圈、各 套環係在各光纖之核心前端互相相向之狀態穿插過共通之 套筒管、以及將各套圈係維持在前述兩條光纖之核心前端 互相接觸狀態之維持機構所構成連接器‘，廣爲人知。 〔特許文獻〕特公平4-693 69號公報 (發明所欲解決之問題） 但是，在波長短、特別是處理由 GaN類半導體雷射所 發射出之波長爲3 5 0〜5 00nm程度之光之裝置方面，得知於 光學元件之光密度高之光通過端面，會堆積起汽化之有機 物質以及與雷射光作光化學反應所產生之物質，亦即產生 所謂之集塵效果。如此當光學元件之光通過端面上附著有 污染物質時，產生爲了獲得既定之光輸出所必要之半導體 雷射驅動電流會提高，雷射光之傳遞損失會增大之問題。 又，得知此集塵效果中，碳化物爲其起因，以及矽氧烷爲 -5- 200416420 其起因。 即使在前述光纖中，在前述傳遞之短波長之光之場合， 在核心之入射端面或是射出端面上會產生集塵效果。因此， 即使在兩條光纖之連接部位，核心之端面彼此遍佈全面完 全不接觸，若是形成該端面之一部與外部氣體接觸之狀態 的話，會產生集塵效果。 在如前述般將兩條光纖作融合之連接構造方面，一般， 由於核心之端面全面彼此完全地接合，所以不會產生集塵 效果。但是，適用於此構造，必須要有專用高價之融合機， 除了作業繁雜之外，亦存在因作業現場而無法準備該融合 機之問題。又，在此連接構造之場合中，要將曾經連接過 之光纖重新連接的話，必須要接受切斷融合部再一次進行 融合作業之繁複。 另一方面，即使在不將兩條光纖融合，各核心之前端 彼此接觸狀態下進行連接之構造中，核心之端面全面完全 接觸的話不會產生集塵效果。在單一模式光纖之場合中， 由於係如核心全體進行接觸般推壓光纖進行連接，不易產 生集塵效果。但是，在多種模式光纖般之核心口徑大之光 纖之場合，使核心端面彼此遍佈全面地接觸係爲困難，因 此會形成核心端面之一部與外部氣體接觸之狀態，容易造 成集麈效果。 本發明係有鑑於前述問題，以提供可防止在互相連接之 光纖前端產生集塵效果，並且不需要龐大融合機能夠簡便 地將兩條光纖連接之構造爲目的。 一 6 - 200416420 又’除此之外，本發明係以提供將兩條光纖一旦連接之 後’能夠簡單地重新連接之光纖之連接構造爲目的。 (三）發明內容 (解決問題之方法） 本發明之第1光纖之連接構造，將兩條光纖不需要融 合’在各核心之前端彼此接觸之狀態下進行連接，其特徵 爲包含核心前端之光纖之前端部係收容於密閉空間內，該 密閉光間係封入有鈍性氣體，或是對於光纖所傳遞之光而 言係透明不會因該光而分解之液體。 本發明之第2光纖之連接構造，與前述同樣地，將兩條 光纖不需要融合，在各核心之前端彼此接觸之狀態下進行 連接，其特徵爲：包含核心前端之光纖之前端部係收容於 連接於流體循環裝置之流體供應口以及流體排出口之容器 內，該容器內充滿有循環之鈍性氣體，或是對於光纖所傳 遞之光而言係透明不會因該光而分解之液體。 又，在本發明之第1以及第2光纖之連接構造中，所謂 的將兩條光纖進行連接，並不單指單一之光纖彼此進行連 接之場合，亦包含光纖陣列彼此又或者是光纖束彼此進行 連接之物件方面光纖陣列彼此又或者是光纖束中之光纖一 對一使其對應之場合。 又，在此所謂的鈍性氣體，乃是指對於構成光纖或是連 接器等之材料爲不具活潑性之氣體，具體而言，可列舉乾 燥之氮氣、氬氣等之稀有氣體。 又，在第1光纖之連接構造方面前述密閉空間內封入鈍 -7- 200416420 性氣體之場合，以及在第2光纖之連接構造方面前述容器 內充滿鈍性氣體之場合，以該鈍性氣體混入有濃度1 ppm以 上之氧氣、鹵素氣體以及/又或者是鹵素化合物之氣體爲 佳。也就是說，作爲封裝之內部氣體環境，則是以（1)鈍性 氣體與濃度lppm以上之氧氣混合之氣體，（2)至少與鈍性 氣體與鹵素氣體以及鹵素化合物氣體中任何一方之氣體作 混合之氣體，（3)鈍性氣體與lppm以上之氧氣、鹵素氣體 以及鹵素化合物之氣體至少與任何一方之氣體作混合之氣 體爲佳。 又，前述鹵素氣體以及鹵素化合物，以含有氟原子爲佳。 又，鹵素化合物氣體以由碳、氮、硫磺以及氙等之氟化物 以及碳、氮、硫磺以及氙等之氯化物所構成之族群中至少 選擇一種爲佳。 所謂鹵素氣體，係指氯氣Cl2、氟氣F2等鹵素氣體，鹵 素化合物之氣體，係指含有氯C1、溴Br、碘I、氟F等鹵 素原子之氣體狀化合物。 鹵素化合物氣體中，可列舉CF3C1、CF2C12、CFC13、 CF3Br、CC14、CCl4-02、C2F4C12、Cl-H2、CF3Br、PC13、CF4、 SF6、NF3、XeF2、C3F8、CHF3等，以氟或是氯與碳元素C、 氮N、硫S、氙Xe之化合物爲佳，特別是以含有氟原子之 氣體爲佳。 又，施加於光纖之射出端面以及入射端面上之包覆之最 表面層，以對於鹵素氣體以及鹵素化合物爲不活潑性材料 加以構成爲佳。該不活潑性材料，以銦、鎵、鋁、鈦、釔 -8- 200416420 之各種氧化物以及銦、鎵、鋁、鈦、釔之各種氮化物所構 成之族群中至少選擇一種爲佳。 又’使用於前述第1與第2光纖之連接構造之鈍性氣體 或是液體，以未含有矽類有機物之物件爲佳。 此外，本發明之第3光纖之連接構造，與前述相同地將 兩條光纖不需要融合，在各核心之前端彼此接觸之狀態下 進行連接，其特徵爲：包含核心前端之光纖之前端部係藉 由以熔融狀態供應到該前端部之後進行凝固，對於光纖所 傳遞之光而言係透明不會因該光而分解之固體與外部加以 隔絕。 在此，前述之固體，可使用低熔點玻璃等爲佳。 又’如前述般不將兩條光纖融合而加以連接之具體構造 中’例如可使用，兩條光纖之前端部分別固定於各套圈上， 套圈係在各光纖之核心前端互相相向之狀態穿插過共通之 套筒管’各套圈維持在前述兩條光纖之核心前端互相接觸 之狀態之構造。 又，本發明之光纖之連接構造中，兩條光纖傳遞之光之 波長以35〇〜5〇〇nm之範圍之場合爲佳。 (發明之效果） 在本發明之第1光纖之連接機構，由於收容著光纖之前 端部之密閉空間內，封入有鈍性氣體，或是對於光纖所傳 遞之光而言係透明不會因該光而分解之液體，如果核心之 前端遍佈全面爲未接觸之場合，該未接觸之部分會成爲與 鈍性氣體以及液體接觸之狀態。因此，引起前述之集麈效 -9 一 200416420 果之有機物等與光纖傳遞之雷射光不會產生光化學反應， 能夠抑制在光纖前端所產生之集塵效果。 又，在本發明之第2光纖之連接機構，由於收容有光纖 之前端部之容器內，充滿有循環之鈍性氣體，或是對於光 纖所傳遞之光而言係透明不會因該光而分解之液體，即使 在此構造中，若是核心之前端遍佈全面而未接觸之場合時， 該未接觸之部分會成爲與鈍性氣體以及液體接觸之狀態。 因此，引起前述之集塵效果之有機物等與光纖傳遞之雷射 光不會產生光化學反應，能夠抑制在光纖前端所產生之集 塵效果。 又，使用於前述第1與第2光纖之連接構造之鈍性氣體 或是液體，使用未含有矽類有機物之物件之場合時，能夠 防止該物件與雷射光進行學反應而產生污染物質。 又，依本發明在第3光纖之連接機構，由於包含核心前 端之光纖之前端部係藉由以熔融狀態供應到該前端部之後 進行凝固，對於光纖所傳遞之光而言係透明不會因該光而 分解之固體與外部加以隔絕，即使在此構造中，若是核心 之前端遍佈全面而未接觸之場合時，該未接觸之部分會成 爲與鈍性氣體以及液體接觸之狀態。從而，在此種構造， 引起前述之集塵效果之有機物等與光纖傳遞之雷射光不會 產生光化學反應，能夠抑制在光纖前端所產生之集塵效果。 以上所說明之本發明之第1到第3光纖之連接構造，由 於並非將兩條光纖進行融合，所以不需要龐大融合機能夠 簡便地將兩條光纖連接之構造。 - 1 0 - 200416420 接著，在兩條光纖之前端部之連接方面，可採用習知之 連接器等之可拆裝之適當機構，如此，除了以熔融後會凝 固之固體覆蓋連接部般之第3連接構造以外，一旦將兩條 之光纖連接之後，能夠簡單地重新連接。 又，依本發明，在光纖之連接機構，特別是在適用兩條 光纖之前端部分別固定於各套圈上，套圈係在各光纖之核 心前端互相相向之狀態穿插過共通之套筒管，各套圈係維 持在前述兩條光纖之核心前端互相接觸之狀態之構造之場 合時，僅令套圈穿插於成爲導件之套筒管，固定於該套圈 之光纖彼此會自動地聚集在同一軸上，光纖之調芯作業亦 變得容易。 又，依本發明，在光纖之連接機構，在封入於密閉空間 或是循環於前述容器內之前述鈍性氣體中，混入有濃度 lppm以上之氧氣、鹵素氣體及/或是鹵素化合物之氣體之 場合時，碳水化合堆積物受到氧化分解而減少的同時，由 於矽類化合物所造成之堆積物受到鹵素氣體加以分解、去 除而減少，特別是能夠獲得信賴性高之光纖之連接構造。 又，施加於光纖之射出端面以及入射端面上之包覆之最 表面層，對於鹵素氣體以及鹵素化合物爲不活潑性材料加 以構成之場合，藉由反映性高知此類氣體能夠防止光纖之 端面惡化。 (四）實施方式 以下，將參照圖面詳細說明本發明之實施形態。 第1圖係本發明之第1實施形態之光纖之連接構造之側 -11- 200416420 視剖面形狀之示意圖。此光纖之連接構造係具有穿插有兩 條多種模式光纖（以下僅稱爲光纖）1 1、1 2之個前端部，將 該前端部加以固定之兩個圓筒形之套圈1 3、1 4，固定於套 圈1 3、1 4之個後端部附近之圓形凸緣1 5、1 6，套圈1 3、1 4 所穿插之連接器24，在凸緣15之內側而安裝於套圈13之 外圍之〇型環27，在凸緣1 6之內側而安裝於套圈14之外 圍之Ο型環2 8。 前述套圈13、14係由陶瓷、玻璃、或金屬、又或是前 述各項之組合所構成之材料所形成。在由陶瓷或是玻璃所 形成之場合時，其側面以電鍍金屬、或是利用噴鍍所進行 之金屬化加工爲佳。然後，安裝光纖11、12之各前端部之 後，將套圈1 3、1 4之前端硏磨成平坦或是球面狀。 又，連接器24乃是具有僅較套圈13、14之外徑稍微大 之內徑之套筒管20之兩端處分別形成凸緣部21、22的同 時，該套筒管20之中央附近形成有具有連通其內部與外部 之貫穿孔23a之氣體導入部23。前述氣體導入部23之外圍 形成有螺紋，該部分係藉由旋合安裝有封閉貫穿孔23a之 閥25。 又，對於前述套筒13、14之凸緣15、16，係如圖中黑 點a所示之部位遍佈全周處例如以焊錫加以固定。此銲錫， 以使用不會發生有機氣體即所謂的無助熔劑銲錫爲佳。 又，分別將套圈1 3、1 4由前端部穿插到連接器24內之 後，前述凸緣15、16其間經由Ο型環27、28，以適當數 量之螺栓29固定於連接器25之凸緣21、22。然後，連接 -12- 200416420 器2 4之內部對於外部係藉由〇型環2 7、2 8以及凸緣1 5、 1 6進行封閉固定。又，由此，固定於套圈1 3、1 4之兩條光 纖1 1、1 2之核心前端互相以同軸狀態進行壓接’光纖1 1、 1 2會互相地作光學性連接。又，前述〇型2 7、2 8以使 用由氟類樹脂所構成之物件爲佳。 如以上所述般在連接光纖1 1、1 2之際，將連接器24之 部分放置於前述之鈍性氣體之氣體環境中’藉由將閥2 5連 接於未圖示之真空幫浦使連接器24之內部進行檢壓之方 式，將鈍性氣體導入連接器24之內部。之後藉由關閉閥2 5 之方式，形成鈍性氣體封入於關閉套圈1 3、1 4形成密閉空 間之連接器2 4內部。 由此，若是光纖1 1、1 2之核心前端遍佈全面未接觸之 場合時，該未接觸之部分會成爲與前述鈍性氣體接觸之狀 態。因此，引起前述之集塵效果之有機物等，與光纖1 1、1 2 傳遞之雷射光，不會產生光化學反應，能夠抑制在光纖1 1、 1 2之前端所產生之集塵效果。 在本實施例之場合中，係令波長爲350〜5 0 0nm之範圍 之雷射光在光纖1 1、1 2傳遞，由於在此波長範圍之雷射光 容易發現前述之集塵效果，可以說本發明之適用特別具有 效果。 又，在將鈍器氣體封入連接器24之內部之前，對連接 器24之內部施加脫氣處理時，能夠更確實地抑制集塵效果。 又，依據本實施形態之光纖之連接構造，由於並非將兩 條光纖1 1、1 2之物件進行融合，不需要龐大之融合機而能 -13- 200416420 夠簡單地將兩條光纖1 1、1 2連接。然後，套圈13、14係 藉由鬆開拆下螺栓2 9之方式，分別能夠簡單地取下連接器 2 4，所以一旦將兩條光纖1 1、1 2連接之後，亦能夠簡單地 重新連接。 此外，在本實施形態之光纖之連接構造中，僅將套圈 13、14穿插過成爲導件之套筒管20，固定於該套圏13、14 之光纖11、12彼此會自動地聚集在同一軸上，光纖之調芯 作業亦變得容易。 又，前述鈍性氣體中最適合係可例舉氮氣、稀有氣體等。 又，此鈍性氣體中，以含有濃度爲lppm以上30 %以下之氧 氣、鹵素氣體以及鹵素化合物中至少一種之氣體爲佳。鹵 素氣體以及鹵素化合物之氣體之最佳實施例係如前面所 述。 當鈍性氣體中含有濃度爲1 ppm以上之氧氣時，能夠更 有效地抑制光纖1 1、1 2之惡化。能夠獲得前述效果之提高， 乃是鈍性氣體中之氧氣，藉由碳水成分之光分解所產生之 固形物進行氧化分解之故。又，爲了使氧氣包含於前述封 閉氣體環境，亦可將乾淨空氣（大氣成分）封入連接器24內 部。 又，即使前述鈍性氣體中含有鹵素氣體以及鹵素化合物 中至少一種，同樣地能夠抑制光纖n、1 2之惡化。雖然此 類鹵素氣體由微量即可發揮抑制惡化效果，爲了獲得顯著 之惡化抑制效果，以含有濃度爲1 Ppm以上之鹵素氣體爲 佳。能夠獲得如此之抑制惡化效果，乃是包含於封閉氣體 一 14- 200416420 環境之鹵素氣體會將藉由有機矽化物氣體之光分解所產生 之堆積物加以分解之故。 又，光纖1 1、1 2之前端互相受到緊密連接固定，不需 要特別形成包覆膜。在未形成包覆膜之場合中，由於不會 產生折射率段差，一般而言，傳遞光之結合效率最高。 但是，根據必要亦可在其前端形成適當之包覆膜。在該 場合中，作爲所披覆之包覆膜之最表面層之材料，若是使 用矽Si、鉬Mo、鉻Cr、錫Sn又或者是銷Zr之氧化物或 是氮化物等對於鹵素氣體具有反應性之材料之場合時，包 覆膜之最表面層會受到蝕刻，降低使用光纖1 1、1 2之裝置 之信賴性。 因此，作爲披覆光纖11、12前端之包覆膜之最表面層 之材料，例如以使用銦、鎵、鋁、鈦、鉅之氧化物或是氮 化物般之對於鹵素氣體爲不活潑性之材料爲佳。 又，爲了將鈍性氣體封入連接器2 4之內部，除了如前 述般進行之外，亦可將加壓後之鈍性氣體通過閥25導入連 接器24之內部。 此外’更可藉由將套圈13、14壓入套筒管20之方式進 行封閉固定’以取代使用〇形環27、28封閉連接器24之 內部。 接著，針對第2實施形態之光纖之連接構造加以說明。 又，在此第2圖中，與第1圖之元件同等之元件覆加上相 同符號，針對該類元件之說明若無特別需要將其省略（以下 均相同）。 一 1 5 - 200416420 在本第2實施形態之光纖之連接構造中，分別固定光纖 1 1、1 2之前端部之之套圈1 3、1 4係穿插過1條圓筒狀之套 筒管3 0，在兩條光纖1 1、1 2之核心前端互相以進行壓接之 狀態下，套圈1 3、1 4係固定於套筒管3 0。此項固定，係例 如在由如圖中黑點a所示之部位遍佈全周處例如以焊錫加 以封閉固定。將前述藉由焊接之固定，藉由在鈍性氣體之 氣體環境中進行之方式，將鈍性氣體封入套筒管3 0之內部。 由此，即使在本實施形態中，亦可獲得與第1實施形態 中同樣之效果。但是在本構造中，要將一旦連接過之光纖 1 1、1 2，各元件維持原狀地重新連接係不可能。 又，在以上所說明之第1以及第2實施形態中，即使使 用對於光纖11、12所傳遞之光而言係透明且不會因該光而 分解之液體取代鈍性氣體，亦可獲得同樣的效果。該液體 例如可適當使用純水。 接著，針對本發明之第3實施形態之光纖之連接構造加 以說明。第3圖及第4圖分別爲第3實施形態之光纖之連 接構造之全體斜視形狀之示意圖與側視剖面形狀之示意 圖。本光纖之連接構造，係將通常之連接器40收容於容器 60內的同時，在容器60內設置有使動性氣體循環之機構之 物件° 前述連接器40，係由穿插過兩個圓筒形之套圈13、14 之前端部之套筒管4 1、具有使維持於套圈i 3、1 4之光纖1 1、 1 2分別通過之孔，收容有套圈1 3、1 4之後端部之外管43、 44、設置於該外管43、44之底面與套圈13、14之間之壓 -16- 200416420 縮彈簧4 5、4 6所構成。 套筒管4 1之兩端外圍上形成有公螺絲，外管4 3、4 4之 前端內圍上形成有母螺絲，兩者可進行旋合。因此，分別 將套圈1 3、1 4之各前端部穿插過套筒管4 1，將後端部穿插 過外管43、44之後，旋轉外管43、44而旋合於套筒管41 時，套圈1 3、1 4之前端彼此會成爲接觸狀態。由此更將外 管43、44加以旋緊時，壓縮彈簧45、46之作用下，套圈13、200416420 (1) Description of the invention: (1) Technical field to which the invention belongs The invention relates to a structure for connecting two optical fibers. (II) Prior technology In the past, the structure connecting two optical fibers is roughly divided into two structures and is known. One type is a structure in which the front ends of two optical fibers are fused with each other while the cores are gathered on the same axis. The other is a structure in which two optical fibers are connected without connecting the front ends of the cores with each other. The latter has a more specific structure. For example, as disclosed in Japanese Patent Publication No. 4-693 69, two ferrules that respectively fix the front ends of two optical fibers, and each ferrule is interspersed in a state where the core front ends of the optical fibers face each other. A connector formed by a common sleeve tube and a maintenance mechanism that maintains each ferrule in a state where the core front ends of the two optical fibers are in contact with each other is widely known. [Patent Document] Japanese Patent Publication No. 4-69369 (Problems to be Solved by the Invention) However, in a short wavelength, in particular, light having a wavelength of about 3 50 to 5 00 nm emitted from a GaN-based semiconductor laser is processed. In terms of the device, it is known that the high-density light passing through the end face of the optical element will accumulate vaporized organic substances and substances produced by the photochemical reaction with laser light, that is, the so-called dust collection effect. In this way, when contamination is attached to the light passing end face of the optical element, the semiconductor laser driving current necessary to obtain a predetermined light output will increase, and the problem of laser light transmission loss will increase. In addition, it is known that in this dust collection effect, carbide is the cause, and siloxane is the cause of -5- 200416420. Even in the aforementioned optical fiber, in the case of the above-mentioned transmitted short-wavelength light, a dust collecting effect is generated on the incident end face or the exit end face of the core. Therefore, even at the connection portion of the two optical fibers, the end faces of the core are completely and completely in contact with each other. If a state where one of the end faces is in contact with the outside air is generated, a dust collecting effect will occur. In the connection structure where two optical fibers are fused as described above, generally, since the end faces of the cores are completely and completely joined to each other, a dust collecting effect does not occur. However, in order to apply this structure, it is necessary to have a special high-priced fusion machine. In addition to the complicated operation, there is also a problem that the fusion machine cannot be prepared due to the job site. In addition, in the case of this connection structure, if the previously-connected optical fiber is to be reconnected, it is necessary to accept the complicated operation of cutting the fusion section and performing the fusion operation again. On the other hand, even in a structure in which the front ends of the cores are in contact with each other without fusing the two optical fibers, the end faces of the cores are completely in contact with each other without causing a dust collection effect. In the case of single-mode optical fiber, since the optical fiber is pushed and connected like the entire core contacts, it is difficult to produce a dust collecting effect. However, in the case of a fiber with a large core diameter, such as a multi-mode fiber, it is difficult to make the core end faces contact each other across the entire surface, so that a part of the core end face is in contact with the outside air, and it is easy to create a gathering effect. The present invention has been made in view of the foregoing problems, and has as its object to provide a structure that can prevent the dust collection effect at the front ends of the optical fibers connected to each other and can easily connect two optical fibers without requiring a large fusion machine. -6-200416420 In addition, the present invention aims to provide an optical fiber connection structure that can be easily reconnected once two optical fibers are connected. (3) Summary of the Invention (Method for Solving the Problem) The first optical fiber connection structure of the present invention does not need to fuse two optical fibers to be connected in a state where the front ends of the cores are in contact with each other. The front end is contained in a closed space, and the sealed light room is sealed with a blunt gas or a liquid that is transparent to the light transmitted by the optical fiber and will not be decomposed by the light. The connection structure of the second optical fiber of the present invention is the same as that described above. The two optical fibers do not need to be fused, and are connected in a state where the front ends of the cores are in contact with each other. In a container connected to a fluid supply port and a fluid discharge port of a fluid circulation device, the container is filled with a circulating inert gas, or a liquid that is transparent to light transmitted by an optical fiber and will not be decomposed by the light. . Furthermore, in the connection structure of the first and second optical fibers of the present invention, the so-called connection of two optical fibers does not refer to a case where a single optical fiber is connected to each other, but also includes an optical fiber array or an optical fiber bundle to each other. Where the optical fiber arrays are connected to each other, or the optical fibers in the optical fiber bundle are one-to-one corresponding. The inert gas used herein refers to a gas that is not reactive to materials constituting an optical fiber, a connector, or the like, and specific examples include rare gases such as dry nitrogen and argon. In addition, in the case where the inert space is sealed with the inert space in the connection structure of the first optical fiber, and when the inert container is filled with the inert gas in the connection structure of the second optical fiber, the inert gas is mixed therein. Oxygen, halogen gas and / or halogen compound gas with a concentration of 1 ppm or more is preferred. In other words, as the internal gas environment of the package, it is (1) a gas mixed with an inert gas and an oxygen concentration of 1 ppm or more, and (2) at least one of an inert gas, a halogen gas, and a halogen compound gas. As a mixed gas, (3) a gas in which at least one of the inert gas and oxygen, a halogen gas, and a halogen compound is mixed with at least one of the gases. The halogen gas and the halogen compound preferably contain a fluorine atom. The halogen compound gas is preferably at least one selected from the group consisting of fluorides of carbon, nitrogen, sulfur, and xenon, and chlorides of carbon, nitrogen, sulfur, and xenon. The halogen gas means a halogen gas such as chlorine gas Cl2, fluorine gas F2, and the gas of a halogen compound means a gaseous compound containing halogen atoms such as chlorine C1, bromine Br, iodine I, and fluorine F. Examples of the halogen compound gas include CF3C1, CF2C12, CFC13, CF3Br, CC14, CCl4-02, C2F4C12, Cl-H2, CF3Br, PC13, CF4, SF6, NF3, XeF2, C3F8, CHF3, and the like. A compound of carbon element C, nitrogen N, sulfur S, and xenon Xe is preferred, and a gas containing a fluorine atom is particularly preferred. The outermost surface layer applied to the exit end face and the entrance end face of the optical fiber is preferably constituted as an inert material for a halogen gas and a halogen compound. The inactive material is preferably at least one selected from the group consisting of various oxides of indium, gallium, aluminum, titanium, and yttrium-8-200416420 and various nitrides of indium, gallium, aluminum, titanium, and yttrium. The inert gas or liquid used in the connection structure of the first and second optical fibers is preferably an object that does not contain a silicon-based organic substance. In addition, the connection structure of the third optical fiber of the present invention does not need to fuse the two optical fibers in the same manner as described above, and connects them in a state in which the front ends of the cores are in contact with each other. By solidifying after being supplied to the front end portion in a molten state, the light transmitted by the optical fiber is transparent and the solid that is not decomposed by the light is isolated from the outside. Here, as the aforementioned solid, a low-melting glass or the like can be preferably used. It can also be used in the specific structure of connecting two optical fibers without fusion as described above. For example, the two ends of the two optical fibers are respectively fixed to the ferrules, and the ferrules are in a state where the core front ends of the optical fibers face each other. Each ferrule inserted through a common sleeve tube maintains a structure in which the front ends of the cores of the two optical fibers are in contact with each other. In the connection structure of the optical fiber of the present invention, it is preferable that the wavelength of light transmitted by the two optical fibers is in a range of 35 to 500 nm. (Effects of the Invention) In the connection mechanism of the first optical fiber of the present invention, since a closed space containing the front end of the optical fiber is enclosed with a blunt gas, or the light transmitted by the optical fiber is transparent, it will not be caused by this. If the liquid is decomposed by light, if the front end of the core is completely untouched, the untouched part will be in contact with inert gas and liquid. Therefore, the organic matter, etc. that caused the aforementioned collection effect will not produce a photochemical reaction with the laser light transmitted by the optical fiber, and can suppress the dust collection effect generated at the front end of the optical fiber. Moreover, in the connection mechanism of the second optical fiber of the present invention, the container containing the front end of the optical fiber is filled with a circulating inert gas, or the light transmitted by the optical fiber is transparent due to the light. Decomposed liquid, even in this structure, if the front end of the core is full and not in contact, the non-contacted portion will be in contact with inert gas and liquid. Therefore, the organic matter or the like that causes the aforementioned dust collection effect does not cause a photochemical reaction with the laser light transmitted from the optical fiber, and the dust collection effect generated at the front end of the optical fiber can be suppressed. In addition, when an inert gas or liquid used in the connection structure of the first and second optical fibers is used, and when an object not containing a silicon-based organic substance is used, it is possible to prevent the object from reacting with laser light to generate a contaminating substance. In addition, according to the present invention, in the connection mechanism of the third optical fiber, since the front end portion of the optical fiber including the core front end is solidified after being supplied to the front end portion in a molten state, the light transmitted by the optical fiber is not transparent due to The light-decomposed solid is isolated from the outside. Even in this structure, if the front end of the core is full and not in contact, the uncontacted part will be in contact with inert gas and liquid. Therefore, in such a structure, the organic matter or the like that causes the aforementioned dust collection effect does not cause a photochemical reaction with the laser light transmitted from the optical fiber, and the dust collection effect generated at the front end of the optical fiber can be suppressed. Since the connection structure of the first to third optical fibers of the present invention described above is not a fusion of two optical fibers, there is no need for a large fusion machine to easily connect the two optical fibers. -1 0-200416420 Next, for the connection of the front ends of the two optical fibers, a suitable removable mechanism such as a conventional connector can be used. In this way, except for covering the connection part with a solid that will solidify after melting, the third In addition to the connection structure, once the two optical fibers are connected, they can be easily reconnected. In addition, according to the present invention, in the connection mechanism of the optical fiber, in particular, the ends are fixed to each ferrule before the application of two optical fibers, and the ferrule is inserted through the common sleeve tube in a state where the core front ends of the optical fibers face each other. When each ferrule is maintained in a state where the core front ends of the two optical fibers are in contact with each other, only the ferrule is inserted into the sleeve tube that becomes the guide, and the optical fibers fixed to the ferrule will automatically gather with each other. On the same axis, the alignment of the optical fiber becomes easy. In addition, according to the present invention, in the connection mechanism of the optical fiber, the above-mentioned inert gas enclosed in a closed space or circulated in the container is mixed with oxygen, a halogen gas, and / or a halogen compound gas having a concentration of 1 ppm or more. In this case, the carbohydrate deposits are reduced by oxidative decomposition, and the deposits caused by silicon compounds are reduced by the decomposition and removal of halogen gas. In particular, a reliable optical fiber connection structure can be obtained. In addition, when the outermost surface layer applied to the exit end face and the entrance end face of the optical fiber is composed of an inactive material for halogen gas and halogen compound, the reflectivity of such gas can prevent deterioration of the end face of the optical fiber. . (4) Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Fig. 1 is a schematic view of a cross-sectional shape of a side of a connection structure of an optical fiber according to a first embodiment of the present invention. The connection structure of this optical fiber is provided with two front end portions through which two multi-mode optical fibers (hereinafter referred to as optical fibers) 1 1 and 1 2 are fixed, and the front end portions are fixed with two cylindrical ferrules 1 3, 1 4. The circular flanges 1 and 5 fixed to the rear end of the ferrule 1 3 and 1 4 and the connector 24 through which the ferrules 1 3 and 1 4 are inserted are installed inside the flange 15 The O-ring 27 on the periphery of the ferrule 13 is installed inside the flange 16 on the O-ring 28 on the periphery of the ferrule 14. The ferrules 13, 14 are made of ceramic, glass, or metal, or a combination of the foregoing. When it is formed of ceramics or glass, it is preferable that the side surface is plated metal or metallized by spraying. Then, after mounting the front ends of the optical fibers 11, 12, the front ends of the ferrules 1 3, 1 4 are honed to be flat or spherical. The connector 24 has flange portions 21 and 22 at both ends of the sleeve tube 20 having an inner diameter slightly larger than the outer diameter of the ferrules 13 and 14, respectively, and the center of the sleeve tube 20 A gas introduction portion 23 having a through hole 23a communicating with the inside and the outside of the gas introduction portion 23 is formed nearby. A thread is formed at the periphery of the gas introduction part 23, and this part is provided with a valve 25 which closes the through hole 23a by screwing. Further, the flanges 15 and 16 of the sleeves 13 and 14 are fixed at positions indicated by black dots a in the figure over the entire circumference, for example, by soldering. This solder is preferably a so-called fluxless solder which does not generate organic gas. In addition, after the ferrules 1 3, 1 4 are inserted into the connector 24 from the front end, the flanges 15 and 16 are fixed to the protrusions of the connector 25 through the O-rings 27 and 28 with an appropriate number of bolts 29.缘 21,22. Then, the inside of the connection -12- 200416420 device 2 4 is closed and fixed to the outside by O-rings 2 7 and 28 and flanges 1 and 16. As a result, the core ends of the two optical fibers 1 1 and 12 fixed to the ferrules 1 3 and 1 4 are crimped to each other coaxially, and the optical fibers 1 1 and 1 2 are optically connected to each other. In addition, it is preferable that the above-mentioned O-types 27 and 28 use an object made of a fluorine-based resin. When connecting the optical fibers 1 1 and 12 as described above, place the part of the connector 24 in the gas environment of the above-mentioned inert gas. 'By connecting the valve 2 5 to a vacuum pump (not shown), The pressure is checked inside the connector 24 by introducing a blunt gas into the inside of the connector 24. Then, by closing the valve 2 5, a blunt gas is formed and sealed in the inside of the connector 2 4 forming a closed space in the closing ferrule 1 3, 1 4. Therefore, if the front ends of the cores of the optical fibers 11 and 12 are all in contact, the non-contacted portions will be in contact with the aforementioned inert gas. Therefore, the organic matter or the like that causes the aforementioned dust collection effect does not cause a photochemical reaction with the laser light transmitted by the optical fibers 1 1 and 1 2, and can suppress the dust collection effect generated at the front ends of the optical fibers 1 1 and 1 2. In the case of this embodiment, the laser light having a wavelength in the range of 350 to 500 nm is transmitted through the optical fibers 1 and 12. Since the laser light in this wavelength range is easy to find the aforementioned dust collection effect, it can be said that The application of the invention is particularly effective. In addition, when a degassing treatment is applied to the inside of the connector 24 before the blunt gas is sealed inside the connector 24, the dust collection effect can be more reliably suppressed. In addition, according to the connection structure of the optical fiber of this embodiment, since the objects of the two optical fibers 1 1 and 12 are not fused, a huge fusion machine is not required and it can be easily -13-200416420. 1 2 connected. Then, the ferrules 13 and 14 can be easily removed by loosening and removing the bolts 29, respectively. Therefore, once the two optical fibers 1 1, 12 are connected, they can be easily re-connected. connection. In addition, in the connection structure of the optical fiber of this embodiment, only the ferrules 13 and 14 are inserted through the sleeve tube 20 which becomes a guide, and the optical fibers 11 and 12 fixed to the ferrules 13 and 14 automatically gather on each other. On the same axis, the alignment of the optical fiber becomes easy. Among the most suitable inert gases, nitrogen and rare gases can be exemplified. The inert gas is preferably a gas containing at least one of an oxygen gas, a halogen gas, and a halogen compound at a concentration of 1 ppm to 30%. Preferred examples of the halogen gas and the gas of the halogen compound are as described above. When the inert gas contains oxygen at a concentration of 1 ppm or more, the deterioration of the optical fibers 11 and 12 can be more effectively suppressed. The improvement in the aforementioned effect can be obtained by the oxidative decomposition of the solids produced by the photodecomposition of carbon water components in the oxygen in the inert gas. In order to include oxygen in the above-mentioned closed gas environment, clean air (atmospheric component) may be sealed inside the connector 24. Further, even if the inert gas contains at least one of a halogen gas and a halogen compound, deterioration of the optical fibers n and 12 can be suppressed similarly. Although such a halogen gas can exhibit a deterioration suppressing effect in a trace amount, in order to obtain a significant deterioration suppressing effect, it is preferable to contain a halogen gas having a concentration of 1 Ppm or more. It is possible to obtain such an effect of suppressing deterioration because the halogen gas contained in the enclosed gas-14-200416420 environment will decompose the deposits generated by the photodecomposition of the organic silicide gas. In addition, the front ends of the optical fibers 1 and 12 are tightly connected and fixed to each other, and it is not necessary to form a coating film in particular. In the case where no coating film is formed, since no refractive index step is generated, generally, the combined efficiency of transmitting light is the highest. However, if necessary, an appropriate coating film may be formed on the tip. In this case, as the material of the outermost layer of the coating film to be coated, if silicon Si, molybdenum Mo, chromium Cr, tin Sn, or oxides or nitrides of pin Zr are used for halogen gas, In the case of a reactive material, the outermost layer of the coating film is etched, reducing the reliability of the device using the optical fibers 1 1 and 12. Therefore, as the material of the outermost layer of the coating film covering the front ends of the optical fibers 11 and 12, for example, indium, gallium, aluminum, titanium, giant oxide, or nitride is used, which is inactive to halogen gas. The material is better. In addition, in order to seal the inert gas inside the connector 24, in addition to the above, the inert gas after pressurization may be introduced into the inside of the connector 24 through the valve 25. In addition, instead of closing the inside of the connector 24 with the o-rings 27 and 28, it can be closed and fixed by pressing the ferrules 13, 14 into the sleeve tube 20. Next, a connection structure of an optical fiber according to the second embodiment will be described. In addition, in this figure, the same components as those in figure 1 are covered with the same symbols, and descriptions of such components are omitted if there is no special need (the same applies hereinafter). 1 15-200416420 In the optical fiber connection structure of the second embodiment, the ferrules 1 3 and 1 4 at the front ends of the optical fibers 1 1 and 12 are respectively fixed through a cylindrical sleeve tube. 30, the ferrules 1 3, 1 4 are fixed to the sleeve tube 30 in a state where the core front ends of the two optical fibers 1 1, 12 are crimped to each other. This fixing is performed, for example, by covering the entire circumference by a portion shown by the black dot a in the figure, for example, by soldering and closing the fixing. The above-mentioned fixing by welding was performed in a gas environment of inert gas, and the inert gas was sealed inside the sleeve tube 30. Therefore, even in this embodiment, the same effects as those in the first embodiment can be obtained. However, in this structure, it is impossible to reconnect the optical fibers 1 and 12 once they are connected, and to reconnect the components as they are. Further, in the first and second embodiments described above, the same can be obtained even if a liquid that is transparent to the light transmitted by the optical fibers 11 and 12 and does not decompose by the light is used instead of the inert gas. Effect. As the liquid, for example, pure water can be suitably used. Next, a connection structure of an optical fiber according to a third embodiment of the present invention will be described. Figures 3 and 4 are a schematic view of the overall oblique shape and a side sectional view of the connection structure of the optical fiber according to the third embodiment, respectively. The connection structure of the optical fiber is an object that circulates a dynamic gas in the container 60 while the ordinary connector 40 is housed in the container 60. The connector 40 is inserted through two cylinders. Shaped ferrules 13, 14 The sleeve tube 4 at the front end 1. It has holes through which the optical fibers 1 1, 1 2 maintained at the ferrules i 3, 1 4 pass, respectively, and contains the ferrules 1 3, 1 4 The outer tubes 43 and 44 at the ends and the pressure between the bottom surfaces of the outer tubes 43 and 44 and the ferrules 13 and 14 are formed by 16-200416420 shrink springs 4 5 and 4 6. Male screws are formed on the periphery of both ends of the sleeve tube 41, and female screws are formed on the inner periphery of the front ends of the outer tubes 4 3, 4 4 so that the two can be screwed together. Therefore, after inserting the front end portions of the ferrules 1 3, 1 4 through the sleeve tube 41, and inserting the rear end portions through the outer tubes 43, 44, the outer tubes 43, 44 are rotated to be screwed onto the sleeve tube 41 At this time, the front ends of the ferrules 1 3, 1 4 will be in contact with each other. Therefore, when the outer tubes 43 and 44 are tightened, under the action of the compression springs 45 and 46, the ferrules 13,
1 4之前端彼此也就是光纖1 1、1 2之前端彼此會成爲壓接狀 態，光纖1 1、1 2會互相作光學#連接。The front ends of the four ends, that is, the front ends of the optical fibers 11 and 12, will be in a crimped state with each other, and the optical fibers 1 1, 12 will be optically connected to each other.
容器60係具有上側箱體6 1與下側箱體62所構成之上 下分割爲二之構造，上側箱體6 1與下側箱體62係經由鉸 鏈6 3可搖動地受到維持，藉由閂鎖金屬零件64在互相一 體化狀態下受到固定。然後上側箱體6 1與下側箱體62分 別設置有氣體供應口 65、氣體排出口 66。又，上側箱體61 與下側箱體62之左右側壁上，分別形成有半圓形之開口， 該部分設置有圓筒形之光纖承接部67、68。此光纖承接部 6 7、6 8例如係由氟類橡膠等之彈性元件所構成，在與通過 其中空部之光纖1 1、1 2之間，以及與呈現受到關閉狀態之 鄕體6 1、62之間維持著氣體密閉狀態。 氣體供應口 65、氣體排出口 66係連接於氣體循環配管 70，在此氣體循環配管70之圖中，係設置有儲存前述鈍性 氣體之除氣槽71以及氣體輸送幫浦72。在本實施例中，藉 由以上之氣體循環配管70、除氣槽71以及氣體輸送幫浦7 2 構成流體循環裝置。 -17- 200416420 光纖1 1、1 2係分別通過光纖承接部67、68之後，使用 連接器40如前述般互相作光學性連接。此連接器4〇之部 分係維持於下側箱體62之底面上，上側箱體6 1由其上方 加以關閉，藉由閂鎖金屬零件64加以鎖緊之方式兩箱體 6 1、6 2維持氣體密閉狀態而一體化。如此使光纖n、1 2之 前端部進行連接之連接器40之部分，成爲收容於容器60 中之狀態。又，兩箱體6 1、62其互相接觸之端面部分，以 藉由施加由氟類橡膠等彈性材料所構成之包覆之方式，使 兩箱體6 1、62間之氣體密閉狀態更加確實爲佳。 連接器4〇之部分收容到容器60中時，氣體輸送幫浦72 會受到驅動，由此，儲氣槽7 1內所儲蓄之鈍性氣體會通過 容器60內受到循環。此鈍性氣體，可使用適合於第丨實施 形態所使用之氣體。 然後，若是光纖11、1 2之核心前端遍佈全面未接觸之 場合時，該未接觸之部分會成爲與前述鈍性氣體接觸之狀 態。因此，引起前述之集塵效果之有機物等與光纖11、12 傳遞之雷射光不會產生光化學反應，能夠抑制在光纖1 1、1 2 之前端所產生之集塵效果。 在本實施例之場合中，係令波長爲3 5 0〜5 00nm之範圍 之雷射光在光纖1 1、1 2傳遞，由於在此波長範圍之雷射光 容易發現前述之集塵效果，可以說本發明之適用特別具有 效果。 又，在使鈍器氣體進行循環之前，對收容有連接器40 之容器6 0之內部施加脫氣處理時，能夠更確實地抑制集塵 -18- 200416420 效果。 又，本實施形態之光纖之連接構造，由於並非將兩條光 纖1 1、1 2之物件進行融合，不需要龐大之融合機而能夠簡 單地將兩條光纖1 1、1 2連接。然後，套圈1 3、1 4係藉由 鬆開拆下連接器4 0之外管4 3、4 4之方式，分別能夠簡單 地取下連接器4 0，所以一旦將兩條光纖1 1、1 2連接之後， 亦能夠簡單地重新連接。 此外，在本實施形態之光纖之連接構造中，僅將套圈 13、14穿插過成爲導件之套筒管41，固定於該套圈13、14 之光纖11、12彼此會自動地聚集在同一軸上，光纖之調芯 作業亦變得容易。 又’在此場合，只要含有濃度爲lppm以上之氧氣、鹵 素氣體以及鹵素化合物中至少一種之氣體，能夠同樣地獲 得在第1實施形態所說明般之效果。又，可使用純水等之 液體，取代前述鈍性氣體之方式，亦與第1實施形態相同。 此外，分別將形成於上側箱體6 1與下側箱體62之氣體 供應口 65、氣體排出口 66關閉，或者是藉由最初即便省略 之方式將容器6 0形成密閉容器的話，亦可將鈍性氣體或是 純水等之液體封入後使用。 接著，參照第5圖針對本發明之第4實施形態加以說明。 在本第4實施形態之光纖之連接構造中，分別固定光纖n、 12之前端部之之套圈13、14係穿插過1條圓筒狀之套筒管 8〇，在光纖1 1、1 2之核心前端互相以進行壓接之狀態下， 套圈1 3、1 4係固定於套筒管8 0。此項固定，係例如在由如 - 1 9 一 200416420 圖中黑點a所示之部位遍佈全周處例如以焊錫加以封閉固 定。 前述套筒管80之中央附近之一部，形成有切口 80a。 然後，如前述般將套圈1 3、14固定於套筒管8 0之後，將 熔融狀態之低熔點玻璃8 1流入此切口 8 0，流動之熔融狀態 之低熔點玻璃會一邊將光纖1 1、1 2其連接部之空氣推出而 通過此部份，逐漸地冷卻後凝固。 又，在本實施例之場合中，雖然令波長爲 3 5 0〜5 00nm 之範圍之雷射光在光纖1 1、1 2傳遞，低熔點玻璃8 1對與 此波長範圍之雷射光而言係爲透明，又爲不因此光受到分 解之物件。 如以上所述般，在本實施形態中，包含核心之前端之光 纖1 1、1 2之前端部藉由在熔融狀態下供應到該前端部後凝 固之低熔點玻璃8 1形成與外部隔絕之狀態。因此，若是光 纖1 1、1 2之核心前端遍佈全面未接觸之場合時，該未接觸 之部分會成爲與低熔點玻璃接觸之狀態。因此，在此構造 中，引起前述之集麈效果之有機物等與光纖11、12傳遞之 雷射光不會產生光化學反應，能夠確實地抑制在光纖11、1 2 之前端所產生之集麈效果。 (五）圖式之簡單說明 第1圖係本發明之第1實施形態之光纖之連接構造之 側視剖面圖。 第2圖係本發明之第2實施形態之光纖之連接構造之 側視剖面圖。 -20 - 200416420 第3圖係本發明之第3實施形態之光纖之連接構造之 全體斜視圖。 第4圖係本發明之第3實施形態之光纖之連接構造之 側視剖面圖。 第5圖係本發明之第4實施形態之光纖之連接構造之 側視剖面圖。 【符號之說明】 1卜 12 多 重 模 式 光 纖 13、 14 套 圈 15、 16 凸 緣 21、 22 連 接 器 之 凸 緣 部 24 連 接 器 25 閥 27、 28 〇 型 環 30 套 筒 管 40 連 接 器 4 1 連 接 器 之 套 筒 管 43、 44 連 接 器 之 外 管 60 容 器 6 5 氣 體 供 應 P 66 氣 體 排 出 □ 67、 68 光 纖 承 接 部 70 /氣 體 循 配 管 7 1 儲 氣 槽 -2卜 200416420 72 氣體輸送幫浦 80 套筒管 8 1 低熔點玻璃The container 60 has a structure in which the upper case 61 and the lower case 62 are divided into two, and the upper case 61 and the lower case 62 are swingably maintained through a hinge 63, and are locked by a latch. The lock metal parts 64 are fixed in an integrated state. Then, the upper case 61 and the lower case 62 are provided with a gas supply port 65 and a gas discharge port 66, respectively. In addition, semicircular openings are formed in the left and right side walls of the upper case 61 and the lower case 62, respectively, and cylindrical fiber receiving portions 67 and 68 are provided in the portions. The optical fiber receiving portions 6 7 and 6 8 are made of, for example, an elastic element such as a fluoro rubber, between the optical fibers 1 1 and 12 passing through the hollow portion, and the carcass 6 which is in a closed state. A gas-tight state is maintained between 62. The gas supply port 65 and the gas discharge port 66 are connected to a gas circulation pipe 70. In the figure, the gas circulation pipe 70 is provided with a degassing tank 71 and a gas delivery pump 72 for storing the aforementioned inert gas. In this embodiment, the above-mentioned gas circulation piping 70, degassing tank 71, and gas transfer pump 7 2 constitute a fluid circulation device. -17- 200416420 After the optical fibers 1 and 12 pass through the fiber receiving portions 67 and 68, respectively, the connectors 40 are optically connected to each other as described above. The part of this connector 40 is maintained on the bottom surface of the lower case 62, and the upper case 6 1 is closed from above, and the two cases 6 1 and 6 2 are locked by the latch metal part 64. It is integrated while maintaining a gas-tight state. In this way, the part of the connector 40 to which the front ends of the optical fibers n and 12 are connected is placed in the container 60. In addition, the end surfaces of the two boxes 6 1 and 62 that are in contact with each other are made more secure by sealing the gas between the two boxes 6 1 and 62 by applying a covering made of an elastic material such as fluorine rubber. Better. When a part of the connector 40 is accommodated in the container 60, the gas transport pump 72 is driven, whereby the inert gas stored in the gas storage tank 71 is circulated through the container 60. As the inert gas, a gas suitable for the first embodiment can be used. Then, if the front ends of the cores of the optical fibers 11 and 12 are completely untouched, the untouched portions will be brought into contact with the aforementioned inert gas. Therefore, the organic matter or the like that causes the aforementioned dust collection effect does not cause a photochemical reaction with the laser light transmitted by the optical fibers 11 and 12, and the dust collection effect generated at the front ends of the optical fibers 11 and 12 can be suppressed. In the case of this embodiment, the laser light having a wavelength in the range of 350 to 500 nm is transmitted through the optical fibers 1 and 12. Since the laser light in this wavelength range can easily find the aforementioned dust collection effect, it can be said that The application of the present invention is particularly effective. In addition, when a degassing treatment is applied to the inside of the container 60 containing the connector 40 before the blunt gas is circulated, the effect of dust collection can be more reliably suppressed -18-200416420. In addition, since the connection structure of the optical fiber of this embodiment does not fuse the objects of the two optical fibers 1 1 and 12, a large fusion machine is not required and the two optical fibers 1 1 and 12 can be simply connected. Then, the ferrules 1 3, 1 4 can be easily removed by removing the connector 4 0 and the outer tube 4 3, 4 4 respectively, so once the two optical fibers 1 1 After connecting 1 and 2, you can simply reconnect. In addition, in the optical fiber connection structure of this embodiment, only the ferrules 13 and 14 are inserted through the sleeve tube 41 which becomes a guide, and the optical fibers 11 and 12 fixed to the ferrules 13 and 14 are automatically gathered on each other. On the same axis, the alignment of the optical fiber becomes easy. In this case, as long as it contains at least one of oxygen, halogen gas, and halogen compound at a concentration of 1 ppm or more, the same effect as described in the first embodiment can be obtained. The method of using a liquid such as pure water instead of the inert gas is also the same as the first embodiment. In addition, if the gas supply port 65 and the gas discharge port 66 formed in the upper case 61 and the lower case 62 are closed, or the container 60 is formed into a closed container by initially omitting the method, the Use inert gas or pure water. Next, a fourth embodiment of the present invention will be described with reference to FIG. 5. In the connection structure of the optical fiber according to the fourth embodiment, the ferrules 13 and 14 which respectively fix the front ends of the optical fibers n and 12 are inserted through a cylindrical sleeve tube 80, and the optical fibers 1 1, 1 In a state where the core front ends of 2 are crimped to each other, the ferrules 1 3, 1 4 are fixed to the sleeve tube 80. This fixing is performed, for example, by fixing the entire area around the area indicated by the black dot a in the figure as shown in the figure. A cutout 80a is formed in a portion near the center of the sleeve tube 80 described above. Then, after fixing the ferrules 1 3 and 14 to the sleeve tube 80 as described above, the molten low-melting glass 8 1 flows into the slit 80, and the flowing low-melting glass will hold the optical fiber 1 1 at the same time. 1, 12 The air of the connection part is pushed out and passes through this part, and gradually cools and solidifies. In the case of this embodiment, although the laser light having a wavelength in the range of 3 50 to 500 nm is transmitted through the optical fibers 1 and 12, the low-melting glass 8 1 is suitable for the laser light in this wavelength range. It is transparent, and it is an object that is not decomposed by this light. As described above, in this embodiment, the front ends of the optical fibers 1 1 and 12 including the front end of the core are isolated from the outside by the low-melting glass 8 1 solidified after being supplied to the front end in a molten state. status. Therefore, if the front ends of the cores of the optical fibers 11 and 12 are all in contact, the non-contact portions will be in contact with the low-melting glass. Therefore, in this structure, the organic matter or the like that causes the aforementioned concentration effect does not cause a photochemical reaction with the laser light transmitted by the optical fibers 11 and 12, and it is possible to reliably suppress the concentration effect generated at the front end of the optical fibers 11, 12 . (V) Brief Description of the Drawings Fig. 1 is a side sectional view of a connection structure of an optical fiber according to a first embodiment of the present invention. Fig. 2 is a side sectional view of a connection structure of an optical fiber according to a second embodiment of the present invention. -20-200416420 Fig. 3 is an overall perspective view of a connection structure of an optical fiber according to a third embodiment of the present invention. Fig. 4 is a side sectional view of a connection structure of an optical fiber according to a third embodiment of the present invention. Fig. 5 is a side sectional view of a connection structure of an optical fiber according to a fourth embodiment of the present invention. [Description of symbols] 1 12 Multi-mode fiber 13, 14 Ferrules 15, 16 Flange 21, 22 Flange portion of connector 24 Connector 25 Valve 27, 28 〇Ring 30 Sleeve tube 40 Connector 4 1 Connector sleeve tube 43, 44 Connector outside tube 60 Container 6 5 Gas supply P 66 Gas discharge □ 67, 68 Fiber receiving section 70 / Gas distribution pipe 7 1 Gas storage tank-2 200416420 72 Gas delivery pump 80 sleeve tube 8 1 low melting glass
-22--twenty two-