Pigtail-type optical receptacle
A pigtail-type optical receptacle includes a ferrule, an optical fiber, a protective member, a sleeve, and a holder. The ferrule has a through-hole extending in an axial direction. The optical fiber is held by the ferrule in a state of being inserted into the through-hole and extends outside the ferrule from a rear end side of the ferrule. The protective member covers a portion of the optical fiber extending outside the ferrule. The sleeve engages an outer surface of the ferrule. The through-hole includes a first region and a second region. The second region is disposed rearward of the first region. The width in an orthogonal direction orthogonal to the axial direction of the through-hole in the second region widens toward the rear end side of the ferrule. The holder holds a portion of the outer surface of the ferrule rearward of the first region.
1. A pigtail-type optical receptacle, comprising:
a ferrule having a tubular configuration and having a through-hole extending in an axial direction;
an optical fiber held by the ferrule in a state of being inserted into the through-hole, the optical fiber extending outside the ferrule from a rear end side of the ferrule;
a protective member covering a portion of the optical fiber extending outside the ferrule;
a sleeve having a tubular configuration, engaging an outer surface of the ferrule, and being mounted on a front end side of the ferrule;
a holder having a tubular configuration, engaging the outer surface of the ferrule, and holding the rear end side of the ferrule; and
a housing having a tubular configuration, engaging an outer surface of the holder, and covering whole of the ferrule and at least a portion of the sleeve around the axial direction,
the through-hole of the ferrule including a first region and a second region, a width in an orthogonal direction of the through-hole in the first region corresponding to a width in the orthogonal direction of the optical fiber, the orthogonal direction being orthogonal to the axial direction, the second region being disposed rearward of the first region, the width in the orthogonal direction of the through-hole in the second region widening toward the rear end side of the ferrule,
the holder holding only at least a portion of an outer surface of the second region rearward of the first region among the outer surface of the ferrule.
2. The receptacle according to claim 1 , wherein a change of the width in the orthogonal direction of the through-hole in the second region has a curved configuration, the curved configuration being convex toward a central axis side of the through-hole.
3. The receptacle according to claim 2 , wherein the through-hole of the ferrule further includes a third region disposed rearward of the second region, and a change of the width in the orthogonal direction of the through-hole in the third region has a linear configuration.
4. The receptacle according to claim 1 , wherein a front end of the protective member is positioned inside the second region of the through-hole.
5. The receptacle according to claim 3 , wherein a front end of the protective member is positioned inside the third region of the through-hole.
6. The receptacle according to claim 1 , wherein the holder holds the rear end side of the ferrule by press-fitting.
7. The receptacle according to claim 1 , wherein a rear end of the holder is positioned rearward of the rear end of the ferrule, the holder surrounds a portion of the optical fiber and a portion of the protective member, and the optical fiber and the protective member further extend outside the holder and are fixedly bonded to the holder by an elastic member filled into the through-hole and into the holder.
8. The receptacle according to claim 7 , wherein an inner perimeter surface of the holder includes: a first inner perimeter portion engaging the outer surface of the ferrule; and a second inner perimeter portion positioned rearward of the first inner perimeter portion, the second inner perimeter portion protruding inward from the first inner perimeter portion and surrounding a portion of the optical fiber and a portion of the protective member, a gap is provided in the axial direction between the second inner perimeter portion and the rear end of the ferrule, and the elastic member is filled also into the gap.
9. The receptacle according to claim 1 , wherein the holder has a first rear end surface and a second rear end surface, and the second rear end surface is recessed frontward of the first rear end surface on an outer perimeter side of the first rear end surface.
10. The receptacle according to claim 1 , wherein the outer surface of the holder includes: a first outer perimeter portion held by the housing; and a second outer perimeter portion provided at a front end portion of the holder, the second outer perimeter portion being recessed inward from the first outer perimeter portion.
11. The receptacle according to claim 1 , wherein the holder includes a chamfer portion between a rear end surface and an inner perimeter surface.
12. The receptacle according to claim 7 , wherein the elastic member includes a protrusion protruding outside the holder on the rear end side of the holder and covering a corner portion between the rear end of the holder and an outer surface of the protective member.
13. The receptacle according to claim 1 , wherein the housing holds the holder by press-fitting.
14. The receptacle according to claim 1 , wherein the outer surface of the ferrule includes a first contact portion contacting an inner perimeter surface of the holder, the outer surface of the holder includes a second contact portion contacting an inner perimeter surface of the housing, and an intermediate point in the axial direction of the second contact portion is positioned rearward of an intermediate point in the axial direction of the first contact portion.