Fiber optic ferrule with smooth internal contours
A fiber optic ferrule includes a body extending from a first end to a second opposite end, with the body including an axial passage extending between the first and the second ends. The axial passage includes a first diameter portion having a diameter of at least 125 microns, a second diameter portion having a diameter of at least 250 microns and less than a diameter of a buffer, and a smooth and continuous transition between the first and the second diameter portions. The second diameter portion is positioned between the first diameter portion and the second end. The axial passage further defines a tapered shape at the second end extending inward from the second end toward the second diameter portion. In certain embodiments, another smooth and continuous transition can be provided between the taper shape and the second diameter portion. In certain embodiments, the axial passage is smooth and continuous between the first and the second ends of the body. A hub holds the ferrule. A method of assembling a terminated fiber optic cable is also provided.
1. A fiber optic ferrule and cable comprising:
a ferrule body extending from a first end to an opposite second end, the ferrule body having an outer cylindrical shape, the ferrule body including a smooth and continuous axial passage extending between the first and the second ends of the ferrule body, the smooth and continuous axial passage of the ferrule body including:
a first diameter portion generally cylindrical in shape adjacent the first end of the ferrule body;
a second diameter portion generally cylindrical in shape positioned between the first diameter portion and the second end of the ferrule body; and
a smooth and continuous transition area extending between and adjoining the first and the second diameter portions;
an optical fiber cable including an inner fiber, an outer coating, and a buffer layer, the outer coating positioned around the inner fiber and the buffer layer positioned around the outer coating, a portion of the outer coating and inner fiber extending beyond an end of the buffer layer and a portion of the inner fiber extending beyond an end of the outer coating; and
a hub mounted around the second end of the ferrule body, the hub including an axial passage;
wherein the first diameter portion of the smooth and continuous axial passage of the ferrule body receives the inner fiber of the optical fiber cable;
wherein the second diameter portion of the smooth and continuous axial passage of the ferrule body receives the outer coating of the optical fiber cable;
wherein the end of the buffer layer of the optical fiber cable is positioned in the axial passage of the hub;
wherein the smooth and continuous axial passage of the ferrule body includes an interior surface; and
wherein a slope of the interior surface is continuous along the length of the ferrule body from the first end of the ferrule body to the opposite second end of the ferrule body.
2. The fiber optic ferrule and cable of claim 1 , wherein the ferrule body is molded of a ceramic material.
3. The fiber optic ferrule and cable of claim 2 , wherein the ceramic material has a maximum average grain size of 0.5 microns and a coefficient of linear thermal expansion of about 10.6×10 −6 /degrees Celsius.
4. The fiber optic ferrule and cable of claim 1 , wherein the first diameter portion of the smooth and continuous axial passage of the ferrule body has a diameter of about 125 microns.
5. The fiber optic ferrule and cable of claim 1 , wherein the end of the buffer layer of the optical fiber cable is positioned in the smooth and continuous transition area.
6. The fiber optic ferrule and cable of claim 1 , wherein the end of the buffer layer of the optical fiber cable is positioned adjacent the smooth and continuous transition area.
7. The fiber optic ferrule and cable of claim 1 , wherein the end of the buffer layer of the optical fiber cable is spaced from the smooth and continuous transition area.
8. The fiber optic ferrule and cable of claim 1 , further comprising an adhesive material within the smooth and continuous axial passage of the ferrule body holding the optical fiber cable to the ferrule body.
9. The fiber optic ferrule and cable of claim 8 , wherein the smooth and continuous transition area defines a pocket that limits an amount of the adhesive material in contact with the optical fiber adjacent the end of the coating and thereby reduces stress concentration imposed on the optical fiber.
10. The fiber optic ferrule and cable of claim 1 , wherein an angle of the interior surface of the smooth and continuous axial passage relative to a central axis of the ferrule body varies along the length of the ferrule body between a minimum of about 0 degrees and a maximum of about 30 degrees.
11. The fiber optic ferrule and cable of claim 10 , wherein a radial distance of the interior surface of the smooth and continuous axial passage from the central axis of the ferrule body varies along the length of the ferrule body between a minimum of about 62.5 microns and a maximum of about 600 microns.
12. The fiber optic ferrule and cable of claim 1 , wherein a radial distance of the interior surface of the smooth and continuous axial passage from a central axis of the ferrule body varies along the length of the ferrule body between a minimum of about 62.5 microns and a maximum of about 600 microns.
13. A fiber optic ferrule comprising:
a ferrule body extending from a first end to an opposite second end, the ferrule body having an outer cylindrical shape, the ferrule body including a smooth and continuous axial passage extending between the first and the second ends of the ferrule body, the smooth and continuous axial passage of the ferrule body including:
an interior surface;
a first diameter portion generally cylindrical in shape adjacent the first end of the ferrule body;
a second diameter portion generally cylindrical in shape positioned between the first diameter portion and the second end of the ferrule body; and
a smooth and continuous transition area extending between and adjoining the first and the second diameter portions; and
wherein a slope of the interior surface is continuous along the length of the ferrule body from the first end of the ferrule body to the second end of the ferrule body.
14. The fiber optic ferrule of claim 13 , wherein the ferrule body is molded of a ceramic material.
15. The fiber optic ferrule of claim 14 , wherein the ceramic material has a maximum average grain size of 0.5 microns and a coefficient of linear thermal expansion of about 10.6×10 −6 /degrees Celsius.
16. The fiber optic ferrule of claim 13 , wherein the first diameter portion of the smooth and continuous axial passage of the ferrule body has a diameter of about 125 microns.
17. The fiber optic ferrule of claim 13 , wherein an angle of the interior surface of the smooth and continuous axial passage relative to a central axis of the ferrule body varies along the length of the ferrule body between a minimum of about 0 degrees and a maximum of about 30 degrees.
18. The fiber optic ferrule of claim 17 , wherein a radial distance of the interior surface of the smooth and continuous axial passage from the central axis of the ferrule body varies along the length of the ferrule body between a minimum of about 62.5 microns and a maximum of about 600 microns.
19. The fiber optic ferrule of claim 13 , wherein a radial distance of the interior surface of the smooth and continuous axial passage from a central axis of the ferrule body varies along the length of the ferrule body between a minimum of about 62.5 microns and a maximum of about 600 microns.