JP2901337B2 - Receptacle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a receptacle in a receptacle-type optical semiconductor device module to which an optical connector can be attached and detached, and more particularly to a receptacle that can suppress reflected light at an end face of an optical fiber inserted and fixed in a ferrule of an optical connector.

[Prior art]

As shown in FIG. 3, the optical connector is an optical fiber 34.
Has a ferrule 31 for inserting and fixing. Such an optical connector is attached to and detached from a receptacle. FIG. 4 shows a conventional receptacle. The conventional receptacle is an optical connector ferrule 31
(FIG. 3) A receptacle housing 45 having a precision hole 41 slightly larger than the outer diameter of FIG. 3, a metal ferrule positioning tool 42 having a through hole 44 smaller than the precision hole 41 and not blocking the optical path, and a ferrule positioning tool 42 And an annular screw 43 fixed to the receptacle housing 45. The ferrule positioning tool 42 performs positioning of the ferrule 31 in the optical axis direction. The optical connector is positioned by the ferrule positioning tool 42 guided by the precision hole 41. As this optical connector, an F01 type single-core optical fiber connector (JIS C5970) is generally used. In an optical semiconductor device module using a conventional receptacle, the optical semiconductor device is generally arranged to face an optical connector via a condenser lens, and is fixed so that the optical axes coincide. The end face of the optical fiber fixed to the ferrule and the light emitting surface or the light receiving surface of the optical semiconductor element are fixed so that light is efficiently coupled via a condenser lens.

[Problems to be solved by the invention]

Light reflection is a phenomenon that occurs at the interface between media having different refractive indices, and the suppression of reflected light is particularly necessary at the converging point of light rays. In a conventional receptacle, for example, when a semiconductor laser is used as an optical semiconductor element, when a light beam enters the optical fiber end face perpendicularly, the reflected light from the optical fiber end face, which is the light condensing point, is about several percent. There is a disadvantage that the operation returns to the laser and the operation of the semiconductor laser becomes unstable. Further, since the conventional receptacle guides the ferrule 31 of the optical connector by the precision hole 41 having an inner diameter slightly larger than the outer diameter, when the optical connector is mounted, the ferrule 31 and the precision hole 41 are not connected. The optical axis shift is likely to occur due to the gap in the diameter direction, and the optical output has a large variation due to the optical axis shift. An object of the present invention is to provide a receptacle that can suppress reflected light from an end face of an optical fiber when an optical connector is attached.

[Means for Solving the Problems]

The receptacle according to the present invention is a detachable receptacle having an optical connector having a ferrule for inserting and fixing an optical fiber, the elastic connector guiding and holding the ferrule, and having an inner diameter slightly smaller than the outer diameter of the ferrule. A first optical surface for physically contacting at least a core portion of the end face of the optical fiber when the ferrule is guided from one opening by the elastic sleeve; A dielectric having a second optical surface facing and oblique with respect to a central axis in a longitudinal direction of the elastic sleeve, and having a refractive index matched to a core of the optical fiber; and the ferrule; Hollow having the same outer diameter and accuracy, and having the dielectric fixed to the end face and inserted into the elastic sleeve from the other opening of the elastic sleeve A cylindrical member; a receptacle having the said dielectric is characterized in that light transmitted through the dielectric is arranged so as to have a beam waist in the first optical surface.

[Operation]

Since the elastic sleeve holds the ferrule and the hollow cylindrical member without any gap in the diametrical direction, the relative displacement between the two is small, and variations in the optical coupling efficiency and the amount of reflection suppression due to the attachment / detachment of the optical connector can be suppressed.

【Example】

Next, the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a receptacle according to one embodiment of the present invention. The receptacle according to the present embodiment has an elastic sleeve 1. The elastic sleeve 1 has an inner diameter slightly smaller than the outer diameter 36 of the ferrule 31 for guiding and holding a ferrule 31 of the optical connector shown in FIG. The elastic sleeve 1 is inserted into a hole formed in the exterior member 7. The hollow cylindrical member 3 has a step 4 at one opening thereof for positioning a dielectric 9 described later. The outer diameter 5 of the hollow cylindrical member 3 is finished to the same outer diameter and precision as the outer diameter 36 of the ferrule 31 (FIG. 3) of the optical connector in order to be guided and held by the elastic sleeve 1. A flange 6 is formed integrally with the other opening of the hollow cylindrical member 3. The flange 6 is fixed to an exterior member 7 with a YAG laser beam weld 8. The elastic sleeve 1, the hollow cylindrical member 3, and the exterior member 7
They are arranged on the same central axis. The dielectric 9 is mounted on the step 4 of the hollow cylindrical member 3 or fixed to a low melting point glass. The dielectric 9 is an optical fiber 34
And the positioning of the ferrule 31. The dielectric 9 is made of quartz glass. The dielectric 9 has an A-plane 10 which is optically polished in a plane. The A surface 10 is fixed to be perpendicular to the central axis of the hollow cylindrical member 3 within a range of ± 0.1 degrees. The B side 11 of the dielectric 9 is the A side
The surface is optically polished at an angle of 8 degrees to 10 and flat. As an optical connector for suppressing reflected light, as shown in FIG. 3, there is the aforementioned F01 type single-core optical fiber connector (JIS C5970). The ferrule 31 of this optical connector has an end face formed by a core portion of an optical fiber 34 fixed on the central axis of the ferrule 31.
The convex spherical surface is optically polished so that 33 is located at the top. With respect to the convex spherical surface, Japanese Patent Publication No. 60-58446 discloses that the radius of curvature of the ferrule end face 35 is set to (1/1) in order to eliminate reflection loss in connection between optical fiber end faces by an optical connector.
lambda) (be _{^{r c 2 + λ 2/4}} ) or more is described.
Here, λ is the optical wavelength, and r _c is the core radius of the optical fiber. This embodiment also uses the optical connector disclosed in the above publication, and has a radius of curvature that is on the market.
An optical connector of about 60 mm is used. The optical connector includes a screw 12 provided on the outer periphery of the exterior member 7.
Is mounted on the receptacle. After the mounting, the core portion 33 of the optical fiber 34 is brought into close contact with and physically contacts the A surface 10 of the dielectric 9 by the compression coil spring 32 in the optical connector. Next, a semiconductor element module using the receptacle of the present invention will be described. FIG. 2 shows a receptacle-type semiconductor laser module using the receptacle shown in FIG. When the housing 20 and the exterior member 7 come into close contact with each other, the condensing lens 14 adjusts the beam waist of the laser light emitted from the semiconductor laser in the semiconductor laser package 15 to the position of the end face of the optical fiber 34 of the mounted optical connector. Here, it is fixed to the semiconductor laser package 15 with low-melting glass so as to coincide with the optical axis direction). The semiconductor laser package 15 and the housing 20 are fixed, and after adjusting so that the coupling efficiency between the laser beam and the optical fiber 34 is maximized (here, in the direction perpendicular to the optical axis), the YAG laser beam welding portion 8 is formed.
Fixed at.

【The invention's effect】

As described above, the receptacle of the present invention couples the ferrule of the optical connector and the hollow cylindrical member having the same outer diameter and precision as the ferrule with the dielectric fixed to the end face, via the elastic sleeve. . Since this elastic sleeve has an inner diameter slightly smaller than the outer diameter of the ferrule and the hollow cylindrical member, it is possible to guide and hold the ferrule and the hollow cylindrical member without any gap in the diametrical direction. Therefore, the reproducibility of the relative position between the ferrule of the optical connector and the hollow cylindrical member is excellent, and the optical axis deviation of the optical fiber due to the attachment / detachment of the optical connector in the optical semiconductor element module whose optical axis is adjusted can be minimized. Similarly, physical contact between the dielectric and the optical fiber can be realized with good reproducibility. In addition, since a dielectric is used as the optical coupling element between the optical fiber and the optical semiconductor element, the optical coupling efficiency is significantly reduced even if the optical fiber is slightly displaced in the radial direction with respect to the optical axis. Without this, the optical fiber and the optical semiconductor element can be optically coupled.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a receptacle according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing an optical semiconductor laser module using the receptacle shown in FIG. 1, and FIG. 3 is an optical connector and a ferrule. FIG. 4 is a view showing an example of a shape in which an end face is optically polished to about R60 mm, and FIG. 4 is a longitudinal sectional view showing a conventional receptacle. DESCRIPTION OF SYMBOLS 1 ... Elastic sleeve, 3 ... Hollow cylindrical member, 4 ... Step, 5 ... Outside diameter, 6 ... Flange, 7 ... Exterior member, 8
…… YAG laser beam welded part, 9 …… Dielectric, 10 …… A
Surface 11, B surface, 12 Screw, 14 Condenser lens, 15
... Optical semiconductor laser package, 20 ... Housing, 31 ...
... ferrule, 32 ... compression coil spring, 33 ... core,
34 ... optical fiber, 35 ... ferrule end face, 36 ... outer diameter, 41 ... precision hole, 42 ... ferrule positioning tool, 43 ...
… Annular screw, 44 …… through hole, 45 …… receptacle housing.

Continuation of the front page (72) Inventor Haruyasu Ando 5-7-1 Shiba, Minato-ku, Tokyo Within NEC Corporation (72) Inventor Tadashi Tadashi 3-20-4 Nishi-Shimbashi, Minato-ku, Tokyo Japan Electric Engineering Co., Ltd. In-company (72) Inventor Yasunori Arai 3-20-4 Nishi-Shimbashi, Minato-ku, Tokyo Japan Electric Engineering Co., Ltd. (56) References JP-A-2-33115 (JP, A) JP-A-2-151820 (JP, A) JP-A-62-170914 (JP, A) JP-A-63-149611 (JP, A)

Claims (3)

(57) [Claims] 1. A receptacle having an optical connector having a ferrule for inserting and fixing an optical fiber, wherein the elastic connector guides and holds the ferrule and has an inner diameter slightly smaller than an outer diameter of the ferrule. A first optical surface for physically contacting at least a core portion of the end face of the optical fiber when the ferrule is guided from one of the openings by the elastic sleeve, and a first optical surface facing the first optical surface; A dielectric having a second optical surface oblique to a central axis in a longitudinal direction of the elastic sleeve, and having a refractive index matched to a core of the optical fiber; and an outer diameter equivalent to the ferrule. And a hollow cylindrical member having accuracy and having the dielectric fixed to the end face and inserted into the elastic sleeve from the other opening of the elastic sleeve. The receptacle according to claim 1, wherein the dielectric is disposed such that light transmitted through the dielectric has a beam waist on the first optical surface. 2. The receptacle according to claim 1, wherein said elastic sleeve is inserted into a hole formed in an exterior member. 3. The receptacle according to claim 1, wherein said hollow cylindrical member has a step for positioning said dielectric.