Optical Connector

Abstract

The optical fiber connector of the present invention includes a housing having a ferrule receiving passageway and a lens receiving portion which is disposed on the front end portion of this ferrule receiving passageway. A central axis is coaxial with the central axis of the ferrule receiving passageway. A spherical lens is fastened to the lens receiving portion and a ferrule is inserted into the ferrule receiving passageway from the rear side and is incorporated with an optical fiber whose front end surface is perpendicular to the central axis. A transparent block having a refractive index that is substantially the same as the refractive indices of the lens and optical fiber is disposed between the lens and the ferrule so that this block contacts the lens, the ferrule, and the optical fiber. A refractive index matching agent having a refractive index substantially the same as the refractive indices of the lens and optical fiber is applied around the contact point between the lens and the block and around the contact surface between the ferrule and the block. The thickness of the block in the direction of beam transmission is set to be the same as the distance to the focal point from the end surface of the lens.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a first embodiment of the optical connector of the present invention;

FIG. 2 is a perspective view of the optical connector shown in FIG. 1;

FIG. 3 is a partial sectional view along line 3-3 in FIG. 1;

FIG. 4 is a sectional view of a second embodiment of the optical connector of the present invention;

FIG. 5 is a perspective view of a female threaded member;

FIGS. 6A and 6B show a male threaded member, with FIG. 6A being a front view, and FIG. 6B being a side view;

FIG. 7 is a sectional view of a conventional optical fiber collimator;

FIG. 8 is a diagram showing the basic construction of a conventional optical fiber rod lens device; and

FIGS. 9A and 9B show a conventional optical connector, with FIG. 9A being a sectional view, and FIG. 9B being an explanatory diagram of the optical connector in a use state.

Claims

1. An optical connector comprising: a housing comprising a ferrule receiving passageway which extends and passes therethrough, and a lens receiving portion which is disposed on the front end portion of the ferrule receiving passageway, and which has a central axis that is coaxial with the central axis of the ferrule receiving passageway;a spherical lens fastened to the lens receiving portion; anda ferrule inserted into the ferrule receiving passageway from the rear side and incorporated with an optical fiber whose front end surface is perpendicular to the central axis, whereina transparent block having a refractive index that is substantially the same as refractive indices of the lens and optical fiber is disposed between the lens and the ferrule so that the block contacts the lens, the ferrule, and the optical fiber,a refractive index matching agent having a refractive index that is substantially the same as the refractive indices of the lens and optical fiber is applied around the contact point between the lens and the block and around the contact surface between the ferrule and the block, andthe thickness of the block in the direction of beam transmission is set to be the same as the distance to the focal point from the end surface of the lens.

2. The optical connector according to claim 1, wherein an anti-reflective coating is provided on the side of the front surface of the lens.

3. The optical connector according to claim 1, wherein the material of the block is quartz glass.

4. The optical connector according to claim 1, wherein the internal diameter of the housing corresponding to the internal diameter of the ferrule receiving passageway has a tolerance of 0.003 mm or less with respect to the external diameter of the ferrule, the true alignment of the center of the internal diameter of the housing is 0.05 mm or better, the perpendicularity of the front end surface of the housing including the lens receiving portion with respect to the internal diameter of the housing is 0.005 mm or better, the circumferential deviation of the lens receiving portion is 0.003 mm or less, and the ferrule is inserted into the ferrule receiving passageway to a length of half of the ferrule or greater.

5. The optical connector according to claim 1, wherein a rounded bevel that conforms to the outer surface of the lens or a 45-degree bevel of 0.05 mm or less is formed in the lens receiving portion of the housing.

6. The optical connector according to claim 1, wherein a positioning pin that is used during the mating with a mating optical connector is provided on the housing, and a positioning pin receiving opening that receives the positioning pin provided on the mating optical connector is formed in the housing.

7. The optical connector according to claim 1, wherein an adhesive injection groove is formed around the lens receiving portion.

8. The optical connector according to claim 1, comprising: a female threaded member which is fastened to a rear end surface of the housing, and which has a ferrule through-opening that passes therethrough and that allows the insertion of the ferrule, the ferrule through-opening having a female threaded section formed on the inner circumferential surface thereof.

9. The optical connector according to claim 8, comprising: a male threaded member which is inserted into the ferrule through-opening of the female threaded member, which has on the outer circumferential surface a male threaded section that is screwed into the female threaded section, which has a through-opening that passes therethrough and that allows the optical fiber extending from the ferrule to be led out to the rear, and which presses the ferrule in the forward direction.

10. The optical connector according to claim 9, comprising: a ferrule fastener having an elastomeric member which is disposed inside the ferrule through-opening in the female threaded member, and which applies an elastic force that presses the ferrule in the rearward direction when the male threaded member presses the ferrule in the forward direction.

11. The optical connector according to claim 10, wherein a slot formed in the outside surface of the ferrule through-opening in the female threaded member allows the optical fiber to be inserted into the ferrule through-opening from the outside of the female threaded member.

12. The optical connector according to claim 10, wherein a slot is formed in the side surface of the male threaded member that allows the optical fiber to be inserted into the through-opening from the outside of the male threaded member.