Means of Coupling Light Into Optical Fibers and Methods of Manufacturing a Coupler

Abstract

The invention relates to a pump coupler ( 2 ) and a manufacturing method. The pump coupler ( 2 ) comprises a least one signal fiber ( 50 ) for outputting optical energy, multiple pump fibers ( 31 ) for inputting optical energy into the signal fiber ( 50 ), and a coupling structure ( 40 ) for coupling the optical energy of the pump fibers ( 31 ) into the signal fiber ( 50 ). A signal feed-through fiber ( 32 ) goes through the coupling structure ( 40 ). In accordance with the invention the coupling structure ( 40 ) is a tapering capillary tube ( 40 ) having a first wide end ( 65 ) and a second narrow end ( 70 ), the pump fibers ( 31 ) are connected to the wide end of the capillary tube ( 40 ), and at least the narrow end ( 70 ) of the capillary tube ( 70 ) is collapsed around the signal fiber ( 32 ).

1 - 8 . (canceled) 
   
   
       9 . An optical coupler, said optical coupler being usable with a first optical fibre and a second optical fibre, said second optical fibre defining a second fibre coupling section and a second fibre transmitting section extending from said second fibre coupling section, said second fibre coupling section defining a radially outwardmost peripheral surface, said radially outwardmost peripheral surface defining a peripheral surface coupling portion, said optical coupler comprising:
 a coupler first end section and a substantially opposed coupler second end section, said coupler first end section defining a first coupling surface;   said optical coupler defining a second coupling surface extending along said coupler first and second end sections;   said first coupling surface being optically couplable with said first optical fibre and said second coupling surface being positionable so as to extend substantially parallel to said peripheral surface coupling portion and to be optically coupled with said peripheral surface coupling portion;   wherein said optical coupler has optical and geometrical properties such that substantially all the light guided to said first coupling surface by said first optical fibre is directed towards said second coupling surface and into said second optical fibre through said peripheral surface coupling portion so as to be guided into said second fibre coupling section for transmission into said second fibre transmitting portion.   
   
   
       10 . An optical coupler as defined in  claim 9 , wherein said optical coupler includes a tapered section tapering in a direction leading from said coupler first end section towards said coupler second end section, said tapered section being located substantially distally relatively to said coupler first end section. 
   
   
       11 . An optical coupler as defined in  claim 10 , wherein said second optical fibre includes a second fibre core and a second fibre cladding extending substantially radially outwardly from said second fibre core, said second optical fibre being positionable such that said second coupling surface and said second fibre core are substantially parallel to each other. 
   
   
       12 . An optical coupler as defined in  claim 10 , wherein said second coupling surface is substantially cylindrical 
   
   
       13 . An optical coupler as defined in  claim 12 , wherein said optical coupler defines a coupler passageway extending along said coupler first and second end sections, said second coupling surface being located substantially peripherally relatively to said coupler passageway. 
   
   
       14 . An optical coupler as defined in  claim 13 , wherein
 said coupler first end section is substantially cylindrical and extends longitudinally substantially parallel to said second coupling surface;   said coupler second end section is substantially frusto-conical and tapers in a direction leading away from said coupler first end section.   
   
   
       15 . An optical coupler as defined in  claim 14 , wherein said coupler passageway is radially substantially centrally located relatively to said coupler first end section. 
   
   
       16 . An optical coupler as defined in  claim 13 , wherein said coupler passageway has a first diameter substantially adjacent said coupler first end section and said coupler passageway has a second diameter substantially adjacent said coupler second end section, said second diameter being substantially smaller than said first diameter. 
   
   
       17 . An optical coupler as defined in  claim 10 , wherein said second coupling surface and said peripheral surface coupling portion are fused to each other. 
   
   
       18 . An optical coupler as defined in  claim 9 , wherein said first coupling surface extends substantially perpendicularly to said second coupling surface. 
   
   
       19 . An optical coupler as defined in  claim 9 , wherein said second coupling surface extends substantially parallel to said peripheral surface coupling portion. 
   
   
       20 . A method for assembling an optical coupling assembly for optically coupling a first and a second optical fibre using an optical coupler, said second optical fibre defining a second fibre coupling section and a second fibre transmitting section extending from said second fibre coupling section, said second fibre coupling section defining a radially outwardmost peripheral surface, said radially outwardmost peripheral surface defining a peripheral surface coupling portion, said optical coupler including a coupler first end section and a substantially opposed coupler second end section, said coupler first end section defining a first coupling surface, said optical fibre defining a second coupling surface extending along said coupler first and second end sections, said method comprising:
 positioning said first optical fibre substantially adjacent to said first coupling surface;   optically coupling said first optical fibre and said first coupling surface to each other;   positioning said second optical fibre such that said second coupling surface is substantially adjacent and substantially parallel to said peripheral surface coupling portion;   optically coupling said second coupling surface and said peripheral surface coupling portion to each other.   
   
   
       21 . A method as defined in  claim 20 , wherein optically coupling said first optical fibre and said first coupling surface to each other is performed before optically coupling said second coupling surface and said peripheral surface coupling portion to each other.