JPH0637803U - Optical attenuator - Google Patents

Abstract

(57) [Summary] [Structure] A capillary whose periphery is coated with ceramic is cut in a direction perpendicular to the optical fiber 2. Next, a flat surface polishing process is performed so that a step 5 is provided on one of the cut end faces 3 of the halves of the capillaries 1a and 1b that have been cut. After that, the cut end surfaces 3 and 3 of the halves of the capillaries 1a and 1b are joined to each other to assemble an optical attenuator using an attenuating section A in which a gap 6 is provided between the optical fibers of the capillaries. [Advantages] The optical attenuator can be provided with higher accuracy than the conventional attenuating part by slitting, and the optical attenuator can be provided very easily and inexpensively.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical attenuator used to adjust the intensity of light in an optical circuit, and more particularly to an optical fixed attenuator that gives a certain amount of attenuation to light.

[0002]

[Prior art]

 In order to change the intensity of transmitted light in the optical circuit, it is sufficient to reflect, scatter, or absorb a part of the incident light. As a means for this, a slit groove is provided in the middle part of the capillary with a rotary cutter, or the capillary is cut and a damping film is vapor-deposited on the cut end face, or a film of the damping film is interposed between the cut end faces. This is done by making an optical attenuator.

[0003]

[Problems to be solved by the device]

 The optical attenuator is required to have high precision in the attenuation rate, and specifically, the tolerance of the attenuation rate is required to be 10% or less. Therefore, in order to satisfy this tolerance, it is necessary to maintain high manufacturing dimensional accuracy, and when using a damping film, it must be made to a strict standard for thickness accuracy, uniformity and durability of the film.

However, in the slitting method of providing the slit groove, only the rotary cutter is currently used to provide the slit groove, and the finished tolerance of the slit groove width when the rotary cutter is used is Since it is difficult to suppress all of them to less than 10%, the attenuation rate error is around 10%, which is inaccurate and has variations.

Further, when the attenuation film is used, since the film thickness is required to have high accuracy as described above, the thickness tolerance is 0.01 μm or less with respect to the thickness of 0.1 μm during vapor deposition. In case of film, the thickness tolerance is required to be less than 1 μm with respect to the thickness of 10 μm, and as a result, it is very troublesome, the production yield is low, and the cost cannot be avoided. . The present invention is intended to address these problems, and the object could be achieved by completing the invention described below.

[0006]

[Means for solving the problem]

 The present invention will be described with reference to the drawings. A capillary in which the periphery of an optical fiber (2) is coated with ceramic or synthetic resin is cut in a direction perpendicular or oblique to the optical fiber (2) to divide into two halves (1a). , 1b) one or both of the cut end faces (3) are processed by ordinary plane polishing to provide a step (5), and then the cut end faces (3, 3) of the bisected capillaries (1a, 1b). The cores of the optical fiber (2) are joined together so that there is no axial misalignment to form the original integral type capillary, and the optical fiber has an attenuating part (A) provided with a void (6) Optical attenuator (B).

In the step processing, if most of the cut end face is processed, it becomes difficult to bond the cut end face. Therefore, the cut end face is processed to such an extent that a gap is provided in the optical fiber portion.

Regarding the joining of the bisected capillaries, an adhesive may be applied to the cut end face to form an integrated type, or the capillaries may be joined by using a connecting ring (8) as shown in FIG. You may make it apply an adhesive agent to the boundary part of a connection ring. Further, the invention of the present application is such that the damping film (27) is interposed in the void portion provided by performing the step processing. The damping film may have a film interposed or may be vapor-deposited.

[0009]

【Example】

 Examples of the present invention will be described below. Example 1 A zirconia capillary having a diameter of 2.5 mm and a length of 10.5 mm was cut, and a flat polishing step was performed to form a step having a width of 20 μm on the cut end surface of one of the capillaries. When an attenuator was assembled using an attenuator incorporating a 20 μm thick attenuating film and the attenuation rate was measured, the attenuation rate was all within the tolerance of 5 dB ± 4% or less. Also, the step processing time was 5 to 10 times as efficient as the conventional slitting processing.

Example 2 A zirconia capillary having a diameter of 2.5 mm and a length of 10.5 mm was cut, and a flat-polishing step process was performed so that a cut end surface of one of the capillaries had a step width of 5 μm. After that, an attenuator was assembled using an attenuator in which 0.1 μm thick chromium was vacuum-deposited on the stepped surface, and the attenuator was measured. All tolerances were 5% or less compared to the attenuator of 10 dB. Entering inside, it became about half of the conventional error.

[0011]

【effect】

 As described above, an optical attenuator having an attenuating section with better accuracy than the attenuating section by slitting can be obtained by cutting the capillary and subjecting it to step processing to form a gap. did it. Moreover, since the step processing is a normal flat surface polishing processing, it can be performed extremely easily and inexpensively.

Further, since it is a flat surface polishing process, the gap width can be freely adjusted, and an attenuator with a small amount of attenuation can be manufactured.

[Brief description of drawings]

FIG. 1 is an explanatory view showing how to make an attenuating part of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the damping unit of the present invention.

FIG. 3 is a cross-sectional view showing another embodiment of the damping unit of the present invention.

FIG. 4 is a sectional view showing another embodiment of the damping unit of the present invention.

FIG. 5 is a sectional view showing an attenuator having an attenuator of the present invention.

FIG. 6 is a cross-sectional view showing a conventional damping section.

FIG. 7 is a cross-sectional view showing a conventional damping section.

[Explanation of symbols]

 A, A ', A "... Attenuator B ... ... Optical attenuator 1a, 1b ... Capillary 2 ... Optical fiber 5 ・ ・ ・ ・ ・ Step 6 ・ ・ ・ ・ ・ ・ ・ Gap 8 ・ ・ ・ ・ ・ ・ ・ Connecting ring 10 ・ ・ ・ ・ ・ ・ ・ Plug frame 20 ・ ・・ ・ ・ ・ ・ ・ ・ Sleeve 27 ・ ・ ・ ・ ・ ・ ・ ・ Attenuation film 30 ・ ・ ・ ・ ・ ・ ・ ・ ・ Hook

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[Procedure amendment]

[Submission date] February 12, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Scope of utility model registration request

[Correction method] Added

[Correction content]

[Scope of utility model registration request]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Name of device

[Correction method] Change

[Correction content]

[Title of device] Optical attenuator

Claims (2)

[Scope of utility model registration request] 1. A capillary in which the periphery of an optical fiber is coated with a ceramic or the like is cut perpendicularly or obliquely to the optical fiber to divide into two, and one or both cut end faces of the capillary are subjected to step processing, and then the divided into two. An optical attenuator, comprising: an attenuating portion formed by joining cut end faces of a capillary to each other so as to provide a gap in an optical fiber of the capillary. 2. The optical attenuator according to claim 1, wherein the attenuating film is interposed in the void provided by cutting the capillary and subjecting it to a step.