Optical device sealing structure and optical deveice manufacturing method

Abstract

To provide an optical device sealing structure capable of simply sealing an optical fiber inserting portion. Provided is a structure that seals an optical device including a metallic case having an optical element disposed therein and an optical fiber inserted through a through hole of the case, wherein a Zn-containing surface is formed on a surface of a bare fiber portion that is formed by partly removing a coating of the optical fiber so as to expose a bare fiber, and wherein an Sn-containing sealing material is charged between the Zn-containing surface and an inner wall of the through hole.

What is claimed is: 
     
         1 . A method of forming a structure that seals an optical device, comprising:
 preparing an optical fiber which comprises a bare fiber and a coating which covers the surface of the bare fiber, wherein the optical fiber has a bare fiber portion having a terminal end from which a coating of the optical fiber has been removed so as to expose a bare fiber,   preparing a metallic case having a through hole, wherein the metallic case includes an optical element and a fiber fixture having a connection hole,   forming a Zn-containing surface on the surface of the bare fiber portion by applying Zn-containing solder to the bare fiber portion,   inserting the bare fiber portion in the metallic case through the through hole of the case so that at least a part of the Zn-containing surface is placed in the through hole,   inserting and fixing the terminal end of the inserted bare fiber portion into the connection hole of the fiber fixture to connect the optical fiber and the optical element, and   charging an Sn-containing sealing material between the surface of the bare fiber portion and an inner wall of the through hole,   wherein   
       the structure includes:
 a metallic case having an optical element disposed therein, 
 an optical fiber which comprises a bare fiber and a coating which covers the surface of the bare fiber, wherein the optical fiber has a bare fiber portion having a terminal end, the bare fiber portion is formed by partly removing a coating of the optical fiber so as to expose a bare fiber, and the bare fiber portion is inserted in the metallic case through a through hole of the case, and 
 a fiber fixture which is disposed in the case, has a connection hole, and connects together a bare fiber of the optical fiber and the optical element, 
 wherein a surface of the bare fiber portion has the Zn-containing surface, and at least a part of the Zn-containing surface is placed in the through hole, an Sn-containing sealing material is charged between the Zn-containing surface and an inner wall of the through hole such that the Sn-containing sealing material directly contacts with the Zn-containing surface and the inner wall of the through hole, and the terminal end of the bare fiber portion is inserted and fixed in the connection hole. 
 
     
     
         2 . The method of forming a structure according to  claim 1 , wherein the step of forming a Zn-containing surface on the surface of the bare fiber portion includes a sub-step wherein the Zn-containing solder is partially applied to the bare fiber portion to generate fixed Zn-containing solder which is fixed to the bare fiber portion. 
     
     
         3 . The method of forming a structure according to  claim 2 , wherein ultrasonic wave and heat are applied in the sub step of applying the Zn-containing solder. 
     
     
         4 . The method of forming a structure according to  claim 1 , wherein the step of forming a Zn-containing surface on the surface of the bare fiber portion includes sub steps of:
 dipping the bare fiber portion into a Zn-containing solder bath and raising the bare fiber portion from the solder bath to solidify the Zn-containing solder attached to the bare fiber portion, and   dipping the solidified Zn-containing solder attached to the bare fiber portion in a dissolution bath, which include a solution that melts the Zn-containing solder, to remove most of the solidified Zn-containing solder from the bare fiber portion and obtain a Zn film having a Zn-containing surface on a surface of the bare fiber portion.   
     
     
         5 . The method of forming a structure according to  claim 1 , wherein ultrasonic wave and heat are applied in the sub step of dipping the bare fiber portion in the Zn-containing solder bath. 
     
     
         6 . The method of forming a structure according to  claim 1 , wherein the Sn-containing sealing material is at least one selected from the group consisting of Sn—Ag-based solder, Sn—In-based solder, Sn—Ag—Cu-based solder, Sn—Cu-based solder, Sn—Ag—In-based solder and Sn—Bi-based solder. 
     
     
         7 . The method of forming a structure that seals an optical device according to  claim 1 , wherein
 the Zn-containing solder is Sn—Zn—Bi-based solder or Sn—Zn—Al-based solder.   
     
     
         8 . A structure that seals an optical device, including
 a metallic case having an optical element disposed therein and a through hole,   an optical fiber which comprises a bare fiber and a coating which covers the surface of the bare fiber, wherein the optical fiber has a bare fiber portion having a terminal end, from which a coating of the optical fiber has been partly removed so as to expose a bare fiber, and the bare fiber portion is inserted in the metallic case through the through hole of the case, and   a fiber fixture which is disposed in the case, has a connection hole, and connects a bare fiber of the optical fiber and the optical element,   wherein a surface of the bare fiber portion has a Zn-containing surface, and at least a part of the Zn-containing surface is placed in the through hole,   an Sn-containing sealing material has been charged between the Zn-containing surface and an inner wall of the through hole such that the Sn-containing sealing material directly contacts with the Zn-containing surface and the inner wall of the through hole, and   the terminal end of the bare fiber portion is inserted and fixed into the connection hole.   
     
     
         9 . The structure that seals an optical device according to  claim 8 , wherein the Zn-containing surface is a Zn-containing surface of a Zn-containing solder which is fixed to the surface of the bare fiber portion. 
     
     
         10 . The structure that seals an optical device according to  claim 8 , wherein the Zn-containing surface is a Zn-containing surface of a Zn film which is formed on the bare fiber portion. 
     
     
         11 . The structure that seals an optical device according to  claim 8 , wherein the Sn-containing sealing material is at least one selected from the group consisting of Sn—Ag-based solder, Sn—-In-based solder, Sn—Ag—Cu-based solder, Sn—Cu-based solder, Sn—Ag—In-based solder and Sn—Bi-based solder. 
     
     
         12 . The structure that seals an optical device according to  claim 8 , wherein the Zn-containing solder is Sn—Zn—Bi-based solder or Sn—Zn—Al-based solder. 
     
     
         13 . A method of forming a structure that seals an optical device, the method comprising:
 preparing an optical fiber which comprises a bare fiber and a coating which covers the surface of the bare fiber, wherein the optical fiber has a bare fiber portion having a terminal end from which a coating of the optical fiber has been removed so as to expose a bare fiber,   preparing a metallic case having a through hole, wherein the metallic case includes an optical element and a fiber fixture having a connection hole,   inserting the bare fiber portion in the metallic case through the through hole of the case,   inserting and fixing the terminal end of the inserted bare fiber portion into the connection hole of the fiber fixture to connect the optical fiber and the optical element, and   charging Zn-containing solder between the surface of the bare fiber portion and an inner wall of the through hole,   wherein   the structure includes   a metallic case having an optical element disposed therein,   an optical fiber which comprises a bare fiber and a coating which covers the surface of the bare fiber, wherein the optical fiber has a bare fiber portion having a terminal end, the bare fiber portion is formed by partly removing a coating of the optical fiber so as to expose a bare fiber, and the bare fiber portion is inserted in the metallic case through a through hole of the case, and   a fiber fixture which is disposed in the case, has a connection hole, and connects a bare fiber portion of the optical fiber and the optical element,   wherein a Zn-containing solder has been charged between a surface of the bare fiber portion and an inner wall of the through hole such that the Sn-containing sealing material directly contacts with the surface of the bare fiber portion and the inner wall of the through hole, and   the terminal end of the bare fiber portion is inserted and fixed in the connection hole.   
     
     
         14 . The method of forming a structure according to  claim 13 , wherein the through hole is provided in the side wall of the case. 
     
     
         15 . The method of forming a structure according to  claim 13 , wherein ultrasonic wave and heat are applied in the step of charging Zn-containing solder. 
     
     
         16 . The method of forming a structure according to  claim 13 , wherein the Zn-containing solder is Sn—Zn—Bi-based solder or Sn—Zn—Al-based solder. 
     
     
         17 . A structure that seals an optical device, including
 a metallic case having an optical element disposed therein and a through hole,   an optical fiber which comprises a bare fiber and a coating which covers the surface of the bare fiber, wherein the optical fiber has a bare fiber portion having a terminal end, from which a coating of the optical fiber has been partly removed so as to expose a bare fiber, and the bare fiber portion is inserted in the metallic case through the through hole of the case, and   a fiber fixture which is disposed in the case, has a connection hole, and connects a bare fiber of the optical fiber and the optical element,   wherein Zn-containing solder has been charged between a surface of the bare fiber portion and an inner wall of the through hole such that the Zn-containing solder directly contacts with the surface of the bare fiber portion and the inner wall of the through hole, and   the terminal end of the bare fiber portion is inserted and fixed in the connection hole.   
     
     
         18 . The structure that seals an optical device according to  claim 17 , wherein the through hole is provided in the side wall of the case. 
     
     
         19 . The structure that seals an optical device according to  claim 17 , wherein the Zn-containing solder is Sn—Zn—Bi-based solder or Sn—Zn—Al-based solder.