Keying for mpo systems

Abstract

Keying may be used to indicate various features of cables, cable connectors, and/or equipment. The keying mechanisms of the connectors systems disclosed herein identifies whether each plug is a pinned plug or a pinless plug. The keying mechanisms disclosed herein identify the number of optical fibers terminated at each plug. For example, one type of keying mechanism may indicate a cable plug manufactured under a 40 Gb/sec standard and another type of keying mechanism may indicate a cable plug manufactured under a 100 Gb/sec standard. The keying mechanisms may indicate a cabling/wiring pattern to be used (e.g., indicates a polarity of the cable). The cables and/or plugs may be color coded based on the keying mechanism. Accordingly, the keying may alert a user to the features of the cable that are not readily apparent upon a cursory inspection.

1 . A plug to be inserted into a receptacle having a first geometry, the plug comprising:
 a ferule that holds at least one optical fiber;   a body having an exterior with a second geometry that corresponds to the first geometry such that the first and second geometries are mating pairs, the second geometry including a keying mechanism that identifies the number of the optical fibers terminated at the plug.   
     
     
         2 . The plug as claimed in  claim 1 , wherein the keying mechanism includes a key. 
     
     
         3 . The plug as claimed in  claim 1 , wherein the keying mechanism is part of a rotational alignment key of the plug. 
     
     
         4 . The plug as claimed in  claim 1 , wherein the plug is color coded based on the keying mechanism. 
     
     
         5 . The plug as claimed in  claim 1 , wherein the plug terminates a patchcord. 
     
     
         6 . The plug as claimed in  claim 1 , wherein the plug includes tactile indicia that correspond to the keying mechanism. 
     
     
         7 . The plug as claimed in  claim 6 , wherein the tactile indicia enable the user to determine the number of fibers terminated by the plug even when the plug is received in the receptacle. 
     
     
         8 . The plug as claimed in  claim 1 , wherein the keying mechanism is disposed at a front of the body. 
     
     
         9 . An optical system having a keying mechanism, the optical system comprising:
 a first coupler including at least a first coupler port and a second coupler port, the second coupler port of the first coupler forming part of the keying mechanism; and   a first patchcord extending between a first end terminated by a first connector and a second end terminated by a second connector, the first patchcord including a plurality of fibers, the first connector of the first patchcord forming a second part of the keying mechanism so that the first connector of the first patchcord plugs into the second coupler port of the first coupler, the keying mechanism identifying an amount of the optical fibers terminated at the first connector.   
     
     
         10 . The optical system of  claim 9 , further comprising:
 a second coupler including at least a first coupler port and a second coupler port, the second coupler port of the second coupler forming part of a respective keying mechanism; and   a second patchcord having a first connector and a second connector, wherein the second connector of the second patchcord forms another part of the keying mechanism of the second coupler port of the second coupler so that the second connector of the second patchcord plugs into the second coupler port of the second coupler.   
     
     
         11 . The optical system of  claim 10 , wherein the keying mechanism of the first coupler is a first keying mechanism and the keying mechanism of the second coupler is a second keying mechanism that is different from the first keying mechanism. 
     
     
         12 . An optical connector for terminating an optical cable, the optical connector comprising:
 a connector body holding a ferrule accessible from a front of the connector body;   a keying mechanism disposed at the front of the connector body, the keying mechanism identifying an amount of optical fibers terminated at the optical connector; and   a tactile indicia disposed at a rear of the connector body, the tactile indicia being associated with the keying mechanism to uniquely identify the keying mechanism.