Optical communications module having a floating ferrule that reduces wiggle loss
A ferrule of an optical communications module is allowed to float to a limited degree within the module housing. Consequently, if a force is exerted on the connector that mates with the optical communications module, the mated ferrules of the module and of the connector moves, or floats, within defined limits so that the ferrules move together rather than relative to one another. In this way, the end faces of the ferrules remain in precise alignment to prevent wiggle losses from occurring due to movement of the connector relative to the module housing.
1. An optical communications module comprising:
a module housing comprising at least first and second housing portions that are secured together to form the module housing, the module housing having a nose portion that defines a receptacle in the module housing for mating with an end portion of a connector;
a module ferrule disposed in the module housing in a floating arrangement that allows the module ferrule to float, or move, inside of the module housing within limits, and wherein the module ferrule is configured to mate with a connector ferrule of the connector in a mated configuration when the end portion of the connector is engaged with the receptacle of the module housing, and wherein if a tilt force is exerted on the connector in a transverse direction to a longitudinal axis of the connector, the tilt force causes the mated configuration of the ferrules to move as a unitary part in an opposing transverse direction within the limits due to the floating arrangement of the module ferrule; and
a module ferrule centering mechanism mechanically coupled to the module ferrule, the module ferrule centering mechanism urging the module ferrule to a centered position if the module ferrule is moved from the centered position as a result of the tilt force exerted on the connector.
2. The optical communications module of claim 1 , wherein the module ferrule and the connector ferrule are mechanical transfer (MT) ferrules.
3. The optical communications module of claim 2 , wherein the connector MT ferrule includes first and second alignment holes formed in a front end face thereof that extend into a body of the connector MT ferrule in directions that are parallel to an optical axis of the connector MT ferrule, and wherein the module MT ferrule has first and second alignment pins disposed on a front end face thereof that extend away from the front end face of the module MT ferrule in directions that are parallel to an optical axis of the module MT ferrule, and wherein when the module MT ferrule and the connector MT ferrule are in the mated configuration, the first and second alignment pins are disposed in the first and second alignment holes, respectively.
4. The optical communications module of claim 2 , wherein the module MT ferrule includes first and second alignment holes formed in a front end face thereof that extend into a body of the module MT ferrule in directions that are parallel to an optical axis of the module MT ferrule, and wherein the connector MT ferrule has first and second alignment pins disposed on a front end face thereof that extend away from the front end face of the connector MT ferrule in directions that are parallel to an optical axis of the connector MT ferrule, and wherein when the module MT ferrule and the connector MT ferrule are in the mated configuration, the first and second alignment pins are disposed in the first and second alignment holes, respectively.
5. The optical communications module of claim 2 , wherein the module MT ferrule is disposed in a cavity of the module housing that is defined by one or more inner walls of the first housing portion and by one or more inner walls of the second housing portion, and wherein at least a portion of the cavity is enlarged to provide space for a portion of the module MT ferrule to float, or move, to a limited extent without encountering said one or more inner walls that define the cavity.
6. The optical communications module of claim 5 , further comprising:
an electromagnetic interference (EMI) shielding device disposed in the module housing in proximity to the module MT ferrule for reducing EMI leakage through the floating arrangement.
7. The optical communications module of claim 6 , wherein the EMI shielding device is an EMI shim that is disposed inside of the cavity in between a back end face of the module MT ferrule and one of said one or more inner walls that define the cavity, and wherein the EMI shim reduces a size of an aperture associated with the enlarged portion of the cavity.
8. The optical communications module of claim 7 , wherein the EMI shim is made of a material that has a high electrical conductivity.
9. The optical communications module of claim 8 , wherein the upper and lower housing portions are made of metal, and wherein the EMI shim is in contact with the upper and lower housing portions.
10. The optical communications module of claim 9 , wherein the EMI shim is made of bronze.
11. The optical communications module of claim 10 , wherein the bronze is nickel-plated.
12. The optical communications module of claim 5 , wherein the module ferrule centering mechanism comprises at least first and second module ferrule centering devices, the first module ferrule centering device being disposed on a first side of the module MT ferrule and the second module ferrule centering device being disposed on a second side of the module MT ferrule that is opposite the first side of the module MT ferrule, the first and second module ferrule centering devices having characteristics of resilience that urge the module MT ferrule in first and second directions, respectively, that are generally opposite one another.
13. The optical communications module of claim 12 , wherein the first and second module ferrule centering devices are made of an elastomeric foam material.
14. The optical communications module of claim 12 , wherein the first and second module ferrule centering devices are metal springs.
15. The optical communications module of claim 1 , further comprising:
an electromagnetic interference (EMI) shielding device disposed in the module housing in proximity to the module ferrule for reducing EMI leakage through the floating arrangement.
16. The optical communications module of claim 15 , wherein the EMI shielding device is an EMI shim that is disposed in between a back end face of the module MT ferrule and an inner wall of the first or second housing portions.
17. The optical communications module of claim 16 , wherein the EMI shim is made of a material that has a high electrical conductivity.
18. The optical communications module of claim 17 , wherein the upper and lower housing portions are made of metal, and wherein the EMI shim is in contact with the upper and lower housing portions.
19. The optical communications module of claim 18 , wherein the EMI shim is made of bronze.
20. The optical communications module of claim 19 , wherein the bronze is nickel-plated.
21. An optical communications system comprising:
an optical communications module comprising:
a module housing comprising at least first and second housing portions that are secured together to form the module housing, the module housing having a nose portion that defines a receptacle in the module housing; and
a module ferrule disposed in the module housing in a floating arrangement that allows the module ferrule to float, or move, inside of the module housing within limits; and
a connector, the connector having an end portion that is engaged with the receptacle of the module housing, the connector comprising:
a connector ferrule, the connector ferrule and the module ferrule being engaged with one another in a mated configuration, and wherein if a tilt force is exerted on the connector in one of an upwards direction or a downwards direction, the tilt force causes the mated configuration of the ferrules to move in an opposite direction to the one of the upwards direction or the downwards direction within the limits as a unitary part due to the floating arrangement.
22. The optical communications system of claim 21 , wherein the optical communications module further comprises:
a module ferrule centering mechanism mechanically coupled to the module ferrule, the module ferrule centering mechanism urging the module ferrule to a centered position if the module ferrule is moved from the centered position as a result of the tilt force exerted on the connector.
23. The optical communications system of claim 22 , wherein the module ferrule and the connector ferrule are mechanical transfer (MT) ferrules, and wherein one of the MT ferrules includes first and second alignment holes and the other of the MT ferrules includes first and second alignment pins, wherein the first and second alignment holes extend from a front end face of the respective MT ferrule into a body of the respective MT ferrule in directions that are parallel to an optical axis of the respective MT ferrule, and wherein the first and second alignment pins are disposed on a front end face of the respective MT ferrule and extend away from the front end face of the respective MT ferrule in directions that are parallel to an optical axis of the respective MT ferrule, and wherein when the module MT ferrule and the connector MT ferrule are in the mated configuration, the first and second alignment pins are disposed in the first and second alignment holes, respectively.
24. The optical communications system of claim 22 , wherein the module ferrule centering mechanism comprises at least first and second module ferrule centering devices, the first module ferrule centering device being disposed on a first side of the module ferrule and the second module ferrule centering device being disposed on a second side of the module ferrule that is opposite the first side of the module ferrule, the first and second module ferrule centering devices having characteristics of resilience that urge the module MT ferrule in first and second directions, respectively, that are generally opposite one another.
25. The optical communications system of claim 24 , wherein the first and second module ferrule centering devices are made of an elastomeric foam material.
26. The optical communications system of claim 21 , wherein the module ferrule is disposed in a cavity of the module housing that is defined by one or more inner walls of the first housing portion and by one or more inner walls of the second housing portion, and wherein at least a portion of the cavity is enlarged to provide space for a portion of the module ferrule to float, or move, to a limited extent without encountering said one or more inner walls that define the cavity.
27. The optical communications system of claim 26 , further comprising:
an electromagnetic interference (EMI) shielding device disposed in the module housing in proximity to the module ferrule for reducing EMI leakage through the floating arrangement.
28. The optical communications system of claim 27 , wherein the EMI shielding device is an EMI shim that is disposed inside of the cavity in between a back end face of the module ferrule and one of said one or more inner walls that define the cavity, and wherein the EMI shim reduces a size of an EMI aperture associated with the enlarged portion of the cavity.
29. The optical communications system of claim 28 , wherein the EMI shim is made of a metal that has a high electrical conductivity, and wherein the upper and lower housing portions are made of metal, and wherein the EMI shim is in contact with the upper and lower housing portions.