Abstract:
A unitary fiber optic ferrule reflects light off an interior lens and through the fiber optic ferrule. Optical fibers can be easily secured in the unitary fiber optic ferrule. An adapter to secure the unitary fiber optic ferrule to a optical component assembly is also presented. The adapter provides a sealing function for the lenses and to provide routing for optical fibers from other assemblies of unitary fiber optic ferrules and adapters.

Description:
REFERENCE TO RELATED CASE 
     This application is a divisional application of U.S. patent application Ser. No. 12/540,193 field Aug. 12, 2009, which in turn claims priority under 35 U.S.C. §119 (e) to provisional application No. 61/118,589, filed on Nov. 28, 2008, the content of both applications are is hereby incorporated by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     A low cost, simple-to-manufacture fiber optic ferrule, adapter, and related assembly is needed in high speed applications. One possible alternative is the MTP connector system, but with the available space for the connections becoming smaller, a smaller format is needed. Similarly, a more simplified connector with a ferrule is also needed so that the connections can be made quickly, reliably, and with minimal parts. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a unitary fiber optic ferrule that includes a main body having a front end, a back end, and a middle portion disposed between the front end and back end, a first opening extending between the back end and the middle portion, the first opening configured to receive at least two optical fibers and having a front wall, a plurality of lenses in optical alignment with the front wall, each of the plurality of lenses having at least one surface exposed to air, and at least two guide pins to align the unitary fiber optic ferrule. 
     In some embodiments, the lenses are disposed in a pocket and below the upper surface of the main body. 
     In some embodiments, there is an optical surface on a bottom surface of the main body, the optical surface in optical alignment with the plurality of lenses. 
     In some embodiments, there are more than one plurality of lenses. 
     In some embodiments, the fiber optic ferrule is molded from an optically clear material. 
     In another aspect, the invention is directed to an adapter to hold and align a unitary fiber optic ferrule that includes a main body having a front end, a back end, and an opening extending therebetween, a first projection extending from the front end and orthogonal to the opening, a second projection extending from the second end and orthogonal to the opening, and a cover portion extending between the front end and back end and partially defining the opening, the cover portion disposed to cover an opening in the unitary fiber optic ferrule. 
     In yet another aspect, the invention is directed to a fiber optic connector assembly that includes a unitary fiber optic ferrule that includes a main body having a front end, a back end, and a middle portion disposed between the front end and back end, a first opening extending between the back end and the middle portion, the first opening configured to receive at least two optical fibers and having a front wall, a plurality of lenses in optical alignment with the front wall, each of the plurality of lenses having at least one surface exposed to air, and at least two guide pins to align the unitary fiber optic ferrule; and an adapter to hold and align the unitary fiber optic ferrule, the adapter includes a main body having a front end, a back end, and an opening extending therebetween, a first projection extending from the front end and orthogonal to the opening, a second projection extending from the back end and orthogonal to the opening, and a cover portion extending between the front end and back end and partially defining the opening, the cover portion disposed to cover an opening in the unitary fiber optic ferrule. 
     Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings. 
     It is to be understood that both the foregoing general description and the following detailed description of the present embodiments of the invention are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention, and together with the description serve to explain the principles and operations of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective exploded view of one embodiment of a unitary fiber optic ferrule, adapter, optical component portion, and fiber optic ribbon according to the present invention; 
         FIG. 2  is a bottom perspective exploded view of the unitary fiber optic ferrule, adapter, optical component portion, and fiber optic ribbon of  FIG. 1 ; 
         FIG. 3  is a cross sectional view of an assembly of the unitary fiber optic ferrule, adapter, optical component portion, and fiber optic ribbon ribbon of  FIG. 1 ; 
         FIG. 4  is a bottom view of the unitary fiber optic ferrule in the adapter of  FIG. 1 ; 
         FIG. 5  is a front view of the unitary fiber optic ferrule and adapter of  FIG. 1  in alignment with the optical component portion; 
         FIG. 6  is a top perspective view of an assembly of a unitary fiber optic ferrule, adapter, optical component portion, and fiber optic ribbon of  FIG. 1 ; 
         FIG. 7  a rear perspective view of an assembly of the unitary fiber optic ferrule, adapter, optical component portion, and fiber optic ribbon of  FIG. 1 ; 
         FIG. 8  is a side view of the assembly of a unitary fiber optic ferrule, adapter, optical component portion, and fiber optic ribbon of  FIG. 1 ; 
         FIG. 9  is a top view of the assembly of a unitary fiber optic ferrule, adapter, optical component portion, and fiber optic ribbon of  FIG. 1 ; 
         FIG. 10  is a bottom view of the assembly of a unitary fiber optic ferrule, adapter, optical component portion, and fiber optic ribbon of  FIG. 1 ; 
         FIG. 11  is a partial view of another embodiment of a ferrule having two rows of optical fibers and lenses to illustrate doubling the density of a fiber optic ferrule according to the present invention; 
         FIG. 12  is a bottom perspective view of another embodiment of a unitary fiber optic ferrule according to the present invention; 
         FIG. 13  is a perspective view of an embodiment of a optical component and a optical component portion according to the present invention that can be used with the unitary fiber-optic ferrule; 
         FIG. 14  is a cross-sectional perspective view of the optical component portion of  FIGS. 13 ; and 
         FIG. 15  is a perspective view of another embodiment of an optical component portion according to the present invention on an optical component assembly; 
         FIG. 16  is a cross-sectional view of  FIG. 15 ; 
         FIG. 17  is a cross-sectional view of the optical component portion of  FIG. 15  and a unitary optical ferrule and adapter according to another embodiment of the present invention; and 
         FIG. 18  is a top perspective view of an adapter according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to the present preferred embodiment(s) of the invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. 
     Referring to  FIGS. 1 and 2 , an exploded perspective view of a fiber optic connector assembly  10 , according to one embodiment of the present invention, includes a unitary fiber optic ferrule  20 , an adapter  60 , an optical component portion  80 , and fiber optic ribbon  90 . As best seen in  FIG. 3 , the unitary fiber optic ferrule  20  includes a main body  22  having a front end  24 , a back end  26 , and a middle portion  28  disposed between the front end  24  and back end  26 . The unitary fiber optic ferrule  20  also has a first opening  30  extending between the back end  26  and the middle portion  28 , the first opening  30  is configured to receive the fiber optic ribbon  90  and having a front wall  32 . The unitary fiber optic ferrule  20  also has a plurality of lenses  34  in optical alignment with the front wall  32  and each of the lenses  34  having at least one surface  36  exposed to air. As illustrated, the lenses  34  are exposed to air in a pocket  38  that is below an upper surface  40  of the main body  22 . The main body  22  also has at least two guide pins  42  to align the unitary fiber optic ferrule  20  with respect to the adapter  60  and the optical component portion  80 , as described below. 
     The unitary fiber optic ferrule  20  is molded in a single mold and does not require any assembly. The main body  22 , lenses  34 , the first opening  30 , and pocket  38  are all molded at the same time. 
     The fiber optic ribbon  90  has optical fibers  92  therein and the first opening  30  is configured to receive at least two optical fibers  92  therein. The front portion of the optical fibers  92  have been stripped and inserted into the first opening  30 . The optical fibers  92  (and fiber optic ribbon  90 ) may be inserted so that the optical fibers  92  engage the front wall  32 . However, it is also possible that the optical fibers  92  stop short of the front wall  32 . The optical fibers  92  are optically and mechanically aligned with the lenses  34 , preferably by using fiber microholes  35  to achieve better alignment with the lenses  34 . While a fiber optic ribbon  90  is illustrated, it is also possible to use individual optical fibers and/or multiple fiber optic ribbons. The lenses  34  reflect the light from the optical fibers  92  downward due to the index changes between the air in the pocket  38  and the optically clear polymer that is used to mold the main body  22 . The light is reflected to an optical surface  44  in the bottom surface of the main body  22  and out of the unitary fiber optic ferrule  20 . Additionally, the first opening  30  is at an angle α relative to the bottom surface of main body  22  (and the transceiver) and the optical surface  44 , the angle preferably being about 9 degrees. The top surface  40  is also disposed at an angle relative to the bottom surface of the main body  22  and the optical surface  44 . The angle formed by first opening  30  and bottom surface and the angle formed by the top surface  40  and the bottom surface can be between zero degrees (parallel) and about 30 degrees, although other angles are possible. The light may also travel in the opposite direction, depending on whether the ferrule is attached to a transceiver, receiver or a transceiver, referred to herein as an “optical component assembly.” 
     The unitary fiber optic ferrule  20  also preferably has two other openings  46 , 48  in the upper surface  40  to allow an index matched epoxy to be used to secure the fiber optic ribbon  90  in the first opening  46  and the optical fibers  92  in the second opening  48 . 
     The main body  22  also has two recessed portions  50  in the bottom surface to engage the adapter or connector  60 . The recessed portions  50  may also have a cut-out portion  52  that engage a corresponding projection from the adapter  60  to secure the unitary fiber optic ferrule  20  in the adapter  60 . 
     The adapter  60  has a main body  62  having a front end  64 , a back end  66 , and an opening  68  extending therebetween. The adapter  60  also has a first projection  70  extending downward from the front end  64  and orthogonal to the opening  68 . The adapter  60  also has a second projection  72  extending downward from the back end  66  and orthogonal to the opening  68 . The first projection  70  is not as wide as the second projection  72  to prevent the adapter  60  (and unitary fiber optic ferrule  20 ) from being inserted into the optical component portion  80  backwards as described below. The adapter  60  also has a cover portion  74  extending between the front end  64  and back end  66  and partially defining the opening  68 , the cover portion  74  disposed to cover the pocket  38  in the unitary fiber optic ferrule  20 . The cover portion  74  seals the pocket  38  and the opening  48  from dust, oil, moisture, or other contaminants to ensure that the lenses  34  do not become contaminated, degrading their reflective properties. The adapter  60  also has side projections  76  that engage the recessed portions  50  of the unitary fiber optic ferrule  20  as discussed above. The upper surface of the cover portion  74  and two side walls  78  make a fiber routing channel  79  for other fiber optic ribbons associated with other assemblies, especially in a tightly packed system. Typically, the other assemblies are spaced close to one another and the angle of the top surface  40  and the first opening  30  allow for proper handling and management of the optical fibers of the adjacent assemblies. 
     The optical component portion  80  illustrated in the figures is only representative of the possible configurations that could be used with the unitary fiber optic ferrule  20  and the adapter  60 . See also  FIGS. 13-17 . The optical component portion  80  has two openings  82  configured to receive the two guide pins  42  to align the unitary fiber optic ferrule  20  with respect to the adapter  60  and the optical component portion  80 . The optical component portion  80  also has an optical opening  84  that corresponds to the optical surface  44  in the bottom surface of the main body  22  to allow the light to pass between the optical fibers  92  and the optical component assembly. It should be noted that while a transceiver is generally illustrated here, the optical component portion could be attached to a transceiver, a receiver (where light passes only from the fibers to the receiver) or a transmitter (where the light passes from the transmitter to the fibers). The front end of the optical component portion  80  has a smaller opening  86  (see  FIGS. 1 &amp; 5 ) than the opening  87  (see  FIGS. 1 &amp; 2 ) at rear end, thereby preventing the adapter  60  from being misaligned with respect to the optical component portion  80 . That is, the wider second projection  72  will not fit within the smaller opening  86 , thereby alerting the user to turn the adapter  60  around. Thus, the first projection  70  and second projection  72  are used to first generally align the adapter  60  and unitary fiber optic ferrule  20  with the optical component assembly, and then the guide pins  42  mate within the openings  82  to finally optically align the components. The optical component portion  80  also has projections  88  that engage at least a portion of the first projection  70  and second projection  72  to tightly hold the adapter  60  on the optical component portion  80 . 
     It should be noted that the unitary fiber optic ferrule  20  may also have two or more rows of openings, lenses, and optical surfaces to increase the density of optical fibers in the connector as illustrated in  FIG. 11 . 
       FIG. 12  illustrates another embodiment of a unitary fiber optic ferrule  20 ′. The unitary fiber optic ferrule  20 ′ has a main body  22 ′ and a first opening  30 ′ extending between the back end  26 ′ and a middle portion  28 ′ also configured to receive at least two optical fibers. Unitary fiber optic ferrule  20 ′ has a plurality of lenses  34 ′ in optical surface  44 ′ rather than in optical alignment with the front wall (not shown) as in the prior embodiment. As a result, the light from the optical fibers is reflected off of a flat surface that is exposed to air in a pocket on the upper side of the unitary fiber optic ferrule  20 ′. The light is then reflected downward toward optical surface  44 ′ and through the plurality of lenses  34 ′. Alternatively, the light could travel in a reverse direction, i.e., through the plurality of lenses  34 ′ to the reflective surface and into the optical fibers. Additionally, the unitary fiber optic ferrule  20 ′ also includes at least two guide pins  42 ′ to align and secure the fiber optic ferrule  20 ′ to an adapter and receiver portion. 
       FIGS. 13-14  illustrate an alternative optical component portion  80 ′ that can be used with the unitary fiber optic ferrules  20 , 20 ′ described above. The optical component portion  80 ′ has an optical opening  84 ′ to align with the optical surface  44  of a fiber optic ferrule. The optical component portion  80 ′ includes an opening  96 ′ that is an optical communication with the optical opening  84 ′. The opening  96 ′ is configured to receive a lens array  98 ′ to transmit light through the optical component portion  80 ′. While the lens array  98 ′ is illustrated as a unitary piece, it may take any form and fall within the scope of the present invention. The optical component portion  80 ′ can be connected to an optical component assembly in a manner that is known in the art. The optical component portion  80 ′ does not illustrate the small and larger openings at either end to provide a key for the adapter, but those openings, or other key features may be included on optical component portion  80 ′. 
       FIGS. 15-17  illustrate another alternative embodiment of a optical component portion  80 ″ and an optical component assembly  100  that includes an optical component  102 , which may include either a vertical cavity surface emitting laser (VCSEL) or a detector array, depending on whether the optical component assembly  100  is to emit or receive light. Additionally, the optical component  102  may also be a waveguide intended to emit or receive light. The optical component  102  is supported by a circuit substrate  104  and connected to drivers (not shown) by appropriate connectors (not shown). 
     The optical component  80 ″ has an optical opening  84 ″ to align with the optical surface  44  of a fiber optic ferrule. The optical component portion  80 ″ includes an opening  96 ″ that is an optical communication with the optical opening  84 ″. The opening  96 ″ is configured to receive a lens array  92 ″ to transmit light through the optical component  80 ″. While the lens array  92 ″ is illustrated as a unitary piece, it may take any form and fall within the scope of the present invention. The optical component  80 ″ is connected to the optical component assembly  100  in a manner that is known in the art. In this embodiment, the optical component  80 ″ has two projections or guide pins  42 ″ rather than the openings in the other embodiments. The guide pins  42 ″ align with openings  82 ″ in an alternative embodiment of a fiber optic ferrule  20 ″ as illustrated in  FIG. 17 . The front end of the optical component  80 ″ also has a smaller opening  86 ″ than the opening  87 ″ at rear end, thereby preventing the adapter  60  from being misaligned with respect to the optical component  80 ″. The optical component  80 ″ also has projections  88 ″ that engage the adapter  60  as noted above. 
       FIG. 17  illustrates a fiber optic ferrule  20 ″ that is essentially the same as noted above, but rather than the guide pins extending from the bottom surface, fiber optic ferrule  20 ″ has openings  82 ″ in the bottom surface to receive the guide pins  42 ″ to align the fiber optic ferrule  20 ″ with the optical component  80 ″. It should be noted that fiber optic ferrule  20 ″ is disposed in an adapter  60  as described above, but the adapter is absent in  FIG. 17  to allow for clearer illustration. 
     The optical component  102  would be the VCSEL when the optical component assembly  100  is in the transmit mode and the light path is from the optical component assembly  100  through the lens array  92 ″, through the optical opening  84 ″, and into the fiber optic ferrule and finally into the optical fibers once the light has been turned through about 81° in the fiber optic ferrule  20 ″. Alternatively, the optical component  102  would be a detector array when the light travels from the optical fibers to the optical opening  84 ″, through the lens array  92 ″ and into the detector array. 
       FIG. 18  illustrates an alternative embodiment of an adapter  60 ″ that can be used with the fiber optic ferrules described above. The adapter  60 ″ has a main body  62 ″ having a front end  64 ″, a back end  66 ″, and an opening  68 ″ extending therebetween. The adapter  60 ″ also has a first projection  70 ″ extending downward from the front end  64 ″ and orthogonal to the opening  68 ″. The adapter  60 ″ also has a second projection  72 ″ extending downward from the back end  66 ″ and orthogonal to the opening  68 ″. The first projection  70 ″ is not as wide as the second projection  72 ″ to prevent the adapter  60 ″ (and unitary fiber optic ferrule) from being inserted into the optical component portion  80  backwards. The adapter  60 ″ also has a cover portion  74 ″ extending between the front end  64 ″ and back end  66 ″ and partially defining the opening  68 ″, the cover portion  74 ″ disposed to cover the pocket  38  in the unitary fiber optic ferrule  20 . The cover portion  74 ″ seals the pocket  38  and the opening  48  from dust, oil, moisture, or other contaminants to ensure that the lenses  34  do not become contaminated, degrading their reflective properties. The adapter  60 ″ also has side projections  76 ″ that engage the recessed portions  50  of the unitary fiber optic ferrule  20  as discussed above. The upper surface of the cover portion  74 ″ and two side walls  78 ″ make a fiber routing channel  79 ″ for other fiber optic ribbons associated with other assemblies, especially in a tightly packed system. In this embodiment of the adapter  60 ″, the cover portion  74 ″ is reduced in size, leaving an opening  75 ″ extending from the back end  66 ″ to a middle portion of the cover portion  74 ″. This allows for the fiber optic ferrule  20  to first be inserted into the adapter  60 ″ and the optical fibers  90  then to be inserted into the fiber optic connector and then secured therein. The opening  75 ″ allows access to the opening  48  so that epoxy (typically an index matching epoxy) can secure the optical fibers in the fiber optic ferrule. It should be noted however that the cover portion  74 ″ still covers and seals the pocket  38  to prevent debris and contaminants from affecting the optical properties of the fiber optic ferrule. 
     At will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Thus it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.