Optical component
Optical transmission lines in optical transmission systems or laser beam source-applied devices, which utilize optical fibers as optical transmission lines, are connected by optically coupling to an optical fiber terminal portion, which is configured by holding the vicinity of the optical fiber terminal portion with a capillary tube, a ferrule or the like at the connecting portions of the transmission lines. With this configuration, minimizing return loss at the optical fiber terminal portion is a key issue. As a solution thereof, a capillary tube made of glass is used; however, since insertion by driving in or press fitting to a metallic tube or the like is impossible, mass production is impossible, accurate processing is impossible, and it is costly due to the characteristics of the glass, there are many restrictions in the usage thereof. With the present invention, by utilizing as material for capillary tubes, translucent ceramics such as alumina ceramics that have not been conventionally considered in any way for using in this field, an optical fiber terminal portion, which can be processed with little return loss and high accuracy and is suitable for mass production, can be provided at low cost.
1. An optical component comprising:
a holding member made of translucent ceramics for holding the vicinity of an end of an optical fiber; and
a through-hole formed in said holding member and into which an optical fiber is to be inserted, wherein the average crystal grain diameter of the translucent ceramics configuring said holding member is 20 μm or greater, and the diameter of each crystal grain within the portion making up at least 50% of the translucent ceramics volume lies between 10 and 40 μm.
2. An optical component comprising:
a holding member made of translucent ceramics for holding the vicinity of an end of an optical fiber; and
a through-hole formed in said holding member into which an optical fiber is to be inserted, wherein total transmittance that is the ratio of the total amount of light passing through said holding member to the total amount of incident light is at least 0.8, namely 80% for light of wavelengths between 0.3 and 5 μm, and linear transmittance, which is transmittance in the direction to which the incident light progresses through said holding member, is at least 0.15/mm, namely 15% per 1 mm in thickness for light of wavelengths between 0.5 and 2 μm.
3. The optical component according to claim 1 , wherein 99.9% or greater of alumina (Al 2 O 3 ) and 200 to 300 ppm magnesium (Mg) by weight are included in the translucent ceramics as the principal components thereof.
4. The optical component according to claim 1 , wherein said through-hole is a single through-hole.
5. The optical component according to claim 1 , wherein said holding member includes at least two through-holes.
6. The optical component according to claim 4 , wherein said through-hole is formed in said holding member such that the center axis of said through-hole coincides with the axis of said holding member.
7. The optical component according to claim 5 , wherein at least one of said through-holes has a circular cross section.
8. The optical component according to claim 5 , wherein said at least two through-holes include:
a first through-hole and;
a second through-hole having a diameter greater than a diameter of said first through-hole formed in said holding member and wherein said holding member further comprises:
a slit having a width less than the diameter of said first through-hole formed between said first and said second through-holes along at least a part of the length of said first through-hole.
9. The optical component according to claim 8 , wherein the width of said slit is no greater than 70% of the diameter of said first through-hole.
10. The optical component according to claim 8 , wherein the width of said slit is at least 20% of the diameter of said first through-hole.
11. The optical component according to claim 8 , wherein the width of said slit is between 20% and 70% of the diameter of said first through-hole.
12. The optical component according to claim 8 , wherein said first through-hole is formed so that a portion of the longitudinal axis of said first through-hole coincides with a portion of the center axis of said holding member.
13. The optical component according to claim 8 , wherein said second through-hole is formed in said holding member such that said slit is formed with a uniform width across the entire length of said first through-hole.
14. The optical component according to claim 8 , wherein the upper limit for the diameter of said second through-hole is determined within a range such that when a liquid adhesive is injected into at least one of said first and said second through-hole in a state where an optical fiber is inserted into each of said first and said second through-holes, the surface tension of said adhesive makes the optical fiber within said second through-hole be parallel and close to the optical fiber within said first through-hole.
15. The optical component according to claim 8 , wherein said first through-hole and said second through-hole are formed in parallel and are adjacent to each other, and said slit is formed along said through-holes such that the outer surface of a second optical fiber inserted into said second through-hole is adjacent to the outer surface of a first optical fiber inserted into said first through-hole while contacting the internal surface of said first through-hole, and said first through-hole is formed in said holdiag member such that the center axis of said first through-hole coincides with the axis of said holding member.
16. The optical component according to claim 8 , wherein said holding member has at least one mark portion such as a reference surface.
17. The optical component according to claim 8 , wherein said holding member has a guide portion for inserting an optical fiber into said first and said second through-holes provided at an end of said holding member, wherein said guide portion is a hole formed at the end of said holding member on the side where the optical fiber is to be inserted, and has a wider opening than the inlet of said first and said second through-holes, as well as having a surface inclined towards said inlet.
18. The optical component according to claim 8 , wherein the distance between longitudinal axes of said first and said second through-holes is between 119 μm and 132 μm, the diameter of said first through-hole is between 125 μm and 129 μm, and the diameter of said second through-hole is at least 130 μm.
19. The optical component according to claim 8 , wherein said holding member is provided with a third through-hole having a diameter greater than a diameter of said first through-hole which communicates with said first through-hole by way of a slit having a width less than the diameter of said first through-hole formed along the length of said first through-hole.
20. The optical component according to claim 18 , wherein the diameter of said second through-hole is between 140 μm and 156 μm.
21. The optical component according to claim 18 , wherein the width of said slit is at least 30 μm.
22. The optical component according to claim 18 , wherein the width of said slit is no greater than 80 μm.
23. The optical component according to claim 18 , wherein the width of said slit is between 30 μm and 80 μm.
24. The optical component according to claim 19 , wherein the distance between longitudinal axes of said first and said third through-holes is between 119 μm and 132 μm, the diameter of said first through-hole is between 125 μm and 129 μm, and the diameter of said third through-hole is at least 130 μm.
25. The optical component according to claim 24 , wherein the diameter of said third through-hole is between 140 μm and 156 μm.
26. The optical component according to claim 24 , wherein the width of said slit formed between said first through-hole and said third through-hole is no greater than 80 μm.
27. The optical component according to claim 24 , wherein the width of said slit formed between said first through-hole and said third through-hole is at least 30 μm.
28. The optical component according to claim 24 , wherein the width of said slit formed between said first through-hole and said third through-hole is between 30 μm and 80 μm.
29. The optical component according to claim 2 , wherein said through-hole is a single through-hole.
30. The optical component according to claim 2 , wherein said holding member has at least two through-holes.
31. The optical component according to claim 29 , wherein said through-hole is formed in said holding member such that the center axis of said through-hole coincides with the axis of said holding member.
32. The optical component according to claim 30 , wherein at least one of said through-holes has a circular cross section.
33. The optical component according to claim 30 , wherein said at least two through-holes include:
a first through-hole and;
a second through-hole having a diameter greater than a diameter of said first through-hole formed in said holding member and wherein said holding member further comprises:
a slit having a width less than the diameter of said first through-hole formed between said first and said second through-holes along at least a part of the length of said first through-hole.
34. The optical component according to claim 33 , wherein the width of said slit is no greater than 70% of the diameter of said first through-hole.
35. The optical component according to claim 33 , wherein the width of said slit is at least 20% of the diameter of said first through-hole.
36. The optical component according to claim 33 , wherein the width of said slit is between 20% and 70% of the diameter of said first through-hole.
37. The optical component according to claim 33 , wherein said first through-hole is formed so that a portion of the longitudinal axis of said first through-hole coincides with a portion of the center axis of said holding member.
38. The optical component according to claim 33 , wherein said second through-hole is formed in said holding member such that said slit is formed with a uniform width across the entire length of said first through-hole.
39. The optical component according to claim 33 , wherein the upper limit for the diameter of said second through-hole is determined within a range such that when a liquid adhesive is injected into at least one of said first and said second through-holes in a state where an optical fiber is inserted into each of said first and said second through-holes, the surface tension of said adhesive makes the optical fiber within said second through-hole be parallel and close to the optical fiber within said first through-hole.
40. The optical component according to claim 33 , wherein said first through-hole and said second through-hole are formed in parallel and are adjacent to each other, and said slit is formed along said through-holes such that the outer surface of a second optical fiber inserted into said second through-hole is adjacent to the outer surface of a first optical fiber inserted into said first through-hole while contacting the internal surface of said first through-hole, and said first through-hole is formed in said holding member such that the center axis of said first through-hole coincides with the axis of said holding member.
41. The optical component according to claim 33 , wherein said holding member has at least one mark portion such as a reference surface.
42. The optical component according to claim 33 , wherein said holding member has a guide portion for inserting an optical fiber into said first and said second through-holes, provided at an end of said holding member, wherein the guide portion is a hole formed at the end of said holding member on the side where the optical fiber is to be inserted, and has a wider opening than the inlet of said first and said second through-holes, as well as having a surface inclined towards the inlet.
43. The optical component according to claim 33 , wherein the distance between longitudinal axes of said first and said second through-holes is between 119 μm and 132 μm, the diameter of said first through-hole is between 125 μm and 129 μm, and the diameter of said second through-hole is at least 130 μm.
44. The optical component according to claim 33 , wherein said holding member is provided with a third through-hole having a diameter greater than a diameter of said first through-hole which communicates with said first through-hole by way of a slit having a width less than the diameter of said first through-hole formed along the length of said first through-hole.
45. The optical component according to claim 43 , wherein the diameter of said second through-hole is between 140 μm and 156 μm.
46. The optical component according to claim 43 , wherein the width of said slit is at least 30 μm.
47. The optical component according to claim 43 , wherein the width of said slit is no greater than 80 μm.
48. The optical component according to claim 43 , wherein the width of said slit is between 30 μm and 80 μm.
49. The optical component according to claim 44 , wherein the distance between longitudinal axes of said first and said third through-holes is between 119 μm and 132 μm, the diameter of said first through-hole is between 125 μm and 129 μm, and the diameter of said third through-hole is at least 130 μm.
50. The optical component according to claim 49 , wherein the diameter of said third through-hole is between 140 μm and 156 μm.
51. The optical component according to claim 49 , wherein the width of said slit formed between said first through-hole and said third through-hole is no greater than 80 μm.
52. The optical component according to claim 49 , wherein the width of said slit formed between said first through-hole and said third through-hole is at least 30 μm.
53. The optical component according to claim 49 , wherein said width of said slit formed between said first through-hole and said third through-hole is between 30 μm and 80 μm.
54. The optical component according to claim 3 , wherein the alumina (Al 2 O 3 ) content by weight in the translucent ceramics configuring said holding member is 99.95% or greater, and the magnesium (Mg) content by weight is approximately 250 ppm.
55. An optical component, which holds the vicinity of an end of an optical fiber, comprising:
a holding member, which is made of translucent ceramics and holds an optical fiber inserted therein; and
a holding member fixture, which has a holding member insert for inserting, fixing and holding said holding member, wherein
said holding member is provided with a through-hole into which an optical fiber is inserted and held, the average crystal grain diameter of the translucent ceramics configuring said holding member is 20 μm or greater, and the diameter of each crystal grain within the portion making up at least 50% of the translucent ceramics volume lies between 10 and 40 μm.
56. The optical component according to claim 53 , wherein said holding member insert is a hole made in said holding member fixture.
57. The optical component according to claim 53 , wherein said holding member insert is provided with a hollow portion that allows said holding member to be fixed and held in said holding member insert by inserting said holding member into said holding member insert by at least one of a press fit and drive means without using an adhesive.
58. The optical component according to claim 53 , wherein 99.9% or greater of alumina (Al 2 O 3 ) and 200 to 300 ppm magnesium (Mg) by weight are included in the translucent ceramics configuring said holding member as the principal components thereof.
59. The optical component according to claim 55 , wherein said through-hole is a single through-hole.
60. The optical component according to claim 55 , wherein at least two through-holes are provided.
61. The optical component according to claim 59 , wherein said through-hole is formed in said holding member such that the center axis of said through-hole coincides with the axis of said holding member.
62. The optical component according to claim 60 , wherein at least one of said through-holes has a circular cross section.
63. The optical component according to claim 60 , wherein said at least two through-holes include:
a first through-hole and;
a second through-hole having a diameter greater than a diameter of said first through-hole formed in said holding member and wherein said holding member further comprises:
a slit having a width less than the diameter of said first through-hole formed between said first and said second through-holes along at least a part of the length of said first through-hole.
64. The optical component according to claim 63 , wherein the width of said slit is no greater than 70% of the diameter of said first through-hole.
65. The optical component according to claim 63 , wherein the width of said slit is at least 20% of the diameter of said first through-hole.
66. The optical component according to claim 63 , wherein the width of said slit is between 20% and 70% of the diameter of said first through-hole.
67. The optical component according to claim 63 , wherein said first through-hole is formed so that a portion of the longitudinal axis of said first through-hole coincides with a portion of the center axis of said holding member.
68. The optical component according to claim 63 , wherein said second through-hole is formed in said holding member such that said slit is formed with a uniform width across the entire length of said first through-hole.
69. The optical component according to claim 63 , wherein the upper limit for the diameter of said second through-hole is determined within a range such that when a liquid adhesive is injected into at least one of said first and said second through-hole in a state where an optical fiber is inserted into each of said first and said second through-holes, the surface tension of said adhesive makes the optical fiber within said second through-hole be parallel and close to the optical fiber within said first through-hole.
70. The optical component according to claim 63 , wherein said first through-hole and said second through-hole are formed in parallel and are adjacent to each other, and said slit is formed along said through-holes such that the outer surface of a second optical fiber inserted into said second through-hole is adjacent to the outer surface of a first optical fiber inserted into said first through-hole while contacting the internal surface of said first through-hole, and said first through-hole is formed in said holding member such that the center axis of said first through-hole coincides with the axis of said holding member.
71. The optical component according to claim 63 , wherein said holding member has at least one mark portion such as a reference surface.
72. The optical component according to claim 63 , wherein said holding member has a guide portion for inserting an optical fiber into said first and said second through-holes, provided at an end of said holding member, wherein said guide portion is a hole formed at the end of said holding member on the side where the optical fiber is to be inserted, and has a wider opening than the inlet of said first and said second through-holes, as well as having a surface inclined towards the inlet.
73. The optical component according to claim 63 , wherein the distance between longitudinal axes of said first and said second through-holes is between 119 μm and 132 μm, the diameter of said first through-hole is between 125 μm and 129 μm, and the diameter of said second through-hole is at least 130 μm.
74. The optical component according to claim 63 , wherein said holding member is provided with a third through-hole having a diameter greater than a diameter of said first through-hole which communicates with said first through-hole by way of a slit having a width less than the diameter of said first through-hole formed along the length of said first through-hole.
75. The optical component according to claim 73 , wherein the diameter of said second through-hole is between 140 μm and 156 μm.
76. The optical component according to claim 73 , wherein the width of said slit is at least 30 μm.
77. The optical component according to claim 73 , wherein the width of said slit is no greater than 80 μm.
78. The optical component according to claim 73 , wherein the width of said slit is between 30 μm and 80 μm.
79. The optical component according to claim 74 , wherein the distance between longitudinal axes of said first and said third through-holes is between 119 μm and 132 μm, the diameter of said first through-hole is between 125 μm and 129 μm, and the diameter of said third through-hole is at least 130 μm.
80. The optical component according to claim 79 , wherein the diameter of said third through-hole is between 140 μm and 156 μm.
81. The optical component according to claim 79 , wherein the width of said slit formed between said first through-hole and said third through-hole is no greater than 80 μm.
82. The optical component according to claim 79 , wherein the width of said slit formed between said first through-hole and said third through-hole is at least 30 μm.
83. The optical component according to claim 79 , wherein the width of said slit formed between said first through-hole and said third through-hole is between 30 μm and 80 μm.
84. The optical component according to claim 57 , wherein said holding member fixture has through-holes configured from a first hole made in said holding member fixture, which is said holding member insert, and a second hole, which is subsequently formed.
85. The optical component according to claim 57 , wherein said holding member fixture is made of metal, a part of an optical fiber protruding from said holding member is inserted into said second hole, and the internal diameter of said first hole is slightly smaller than the external diameter of said holding member.
86. The optical component according to claim 58 , wherein the alumina (Al 2 O 3 ) content by weight in the translucent ceramics configuring said holding member is 99.95% or greater, and the magnesium (Mg) content by weight is approximately 250 ppm.
87. The optical component according to claim 58 , wherein total transmittance that is the ratio of the total amount of light passing through the translucent ceramics to the total amount of incident light is at least 0.8, namely 80% for light of wavelengths between 0.3 and 5 μm, and linear transmittance, which is transmittance in the direction to which the incident light progresses through the translucent ceramics configuring said holding member, is at least 0.15/mm, namely 15% per 1 mm in thickness for light of wavelengths between 0.5 and 2 μm.
88. The optical component according to claim 58 , wherein said through-hole is a single through-hole.
89. The optical component according to claim 58 , wherein said holding member includes at least two through-holes.
90. The optical component according to claim 88 , wherein said through-hole is formed in said holding member such that the center axis of said through-hole coincides with the axis of said holding member.
91. The optical component according to claim 89 , wherein at least one of said through-holes has a circular cross section.
92. The optical component according to claim 89 , wherein said at least two through-holes include:
a first through-hole and;
a second through-hole having a diameter greater than a diameter of said first through-hole formed in said holding member and wherein said holding member further comprises:
a slit having a width less than the diameter of said first through-hole formed between said first and said second through-holes along at least a part of the length of said first through-hole.
93. The optical component according to claim 92 , wherein the width of said slit is no greater than 70% of the diameter of said first through-hole.
94. The optical component according to claim 92 , wherein the width of said slit is at least 20% of the diameter of said first through-hole.
95. The optical component according to claim 92 , wherein the width of said slit is between 20% and 70% of the diameter of said first through-hole.
96. The optical component according to claim 92 , wherein said first through-hole is formed so that a portion of the longitudinal axis of said first through-hole coincides with a portion of the center axis of said holding member.
97. The optical component according to claim 92 , wherein said second through-hole is formed in said holding member such that said slit is formed with a uniform width across the entire length of said first through-hole.
98. The optical component according to claim 92 , wherein the upper limit for the diameter of said second through-hole is determined within a range such that when a liquid adhesive is injected into at least one of said first and said second through-hole in a state where an optical fiber is inserted into each of said first and said second through-holes, the surface tension of said adhesive makes the optical fiber within said second through-hole be parallel and close to the optical fiber within said first through-hole.
99. The optical component according to claim 92 , wherein said first through-hole and said second through-hole are formed in parallel and are adjacent to each other, and said slit is formed along said through-holes such that the outer surface of a second optical fiber inserted into said second through-hole is adjacent to the outer surface of a first optical fiber inserted into said first through-hole while contacting the internal surface of said first through-hole, and said first through-hole is formed in said holding member such that the center axis of said first through-hole coincides with the axis of said holding member.
100. The optical component according to claim 92 , wherein said holding member has at least one mark portion such as a reference surface.
101. The optical component according to claim 92 , wherein said holding member has a guide portion for inserting an optical fiber into said first and said second through-holes, provided at an end of said holding member, wherein said guide portion is a hole formed at the end of said holding member on the side where the optical fiber is to be inserted, and has a wider opening than the inlet of said first and said second through-holes, as well as having a surface inclined towards said inlet.
102. The optical component according to claim 92 , wherein the distance between longitudinal axes of said first and said second through-holes is between 119 μm and 132 μm, the diameter of said first through-hole is between 125 μm and 129 μm, and the diameter of said second through-hole is at least 130 μm.
103. The optical component according to claim 92 , wherein said holding member is provided with a third through-hole having a diameter greater than a diameter of said first through-hole which communicates with said first through-hole by way of a slit having a width less than the diameter of said first through-hole formed along the length of said first through-hole.
104. The optical component according to claim 102 , wherein the diameter of said second through-hole is between 140 μm and 156 μm.
105. The optical component according to claim 102 , wherein the width of said slit is at least 30 μm.
106. The optical component according to claim 102 , wherein the width of said slit is no greater than 80 μm.
107. The optical component according to claim 102 , wherein the width of said slit is between 30 μm and 80 μm.
108. The optical component according to claim 103 , wherein the distance between longitudinal axes of said first and said third through-holes is between 119 μm and 132 μm, the diameter of said first through-hole is between 125 μm and 129 μm, and the diameter of said third through-hole is at least 130 μm.
109. The optical component according to claim 108 , wherein the diameter of said third through-hole is between 140 μm and 156 μm.
110. The optical component according to claim 108 , wherein the width of said slit formed between said first through-hole and said third through-hole is no greater than 80 μm.
111. The optical component according to claim 108 , wherein the width of said slit formed between said first through-hole and said third through-hole is at least 30 μm.
112. The optical component according to claim 108 , wherein the width of said slit formed between said first through-hole and said third through-hole is between 30 μm and 80 μm.