Splicing and connectorization of photonic crystal fibres

Abstract

A method of coupling a spliceable optical fibre for transmission of light in its longitudinal direction to an optical component, the method comprising (A) providing the spliceable optical fibre, said spliceable optical fibre comprising: (a) a core region ( 10, 20, 25, 30, 110 ); and (b) a microstructured cladding region, said cladding region surrounding said core region and comprising: (b1) an inner cladding region with inner cladding features ( 13, 22, 112 ) arranged in an inner cladding background material ( 11, 21, 111 ) with a refractive index n1, said inner cladding features comprising thermally collapsible holes or voids, and (b2) an outer cladding region with an outer cladding background material ( 12, 24, 114 ) with a refractive index n2; said spliceable optical fibre having at least one end; (B) collapsing said thermally collapsible holes or voids by heating said least one end of said spliceable optical fibre; and (C) coupling said collapsed spliceable optical fibre end to the optical component. A spliceable optical fibre; a preform for producing a spliceable optical fibre; a method of producing a spliceable optical fibre comprising drawing of the preform; a heat-treated spliceable optical fibre; an article comprising a spliceable optical fibre is further disclosed.

1 - 33 . (canceled)  
   
   
       34 . A method of coupling a spliceable optical fiber for transmission of light in its longitudinal direction to an optical component, the method comprising: 
 (A) providing the spliceable optical fiber, said spliceable optical fiber comprising:    (a) a core region; and    (b) a microstructured cladding region, said cladding region surrounding said core region and comprising:    (b1) an inner cladding region with inner cladding features arranged in an inner cladding background material with a refractive index n1, said inner cladding features comprising thermally collapsible holes or voids, and    (b2) an outer cladding region with an outer cladding background material with a refractive index n2; 
 said spliceable optical fiber having at least one end;  
   (B) collapsing said thermally collapsible holes or voids by heating said least one end of said spliceable optical fiber; and    (C) coupling said collapsed spliceable optical fibre end to the optical component.    
   
   
       35 . The method according to  claim 34 , wherein said collapsing of said thermally collapsible holes or voids being gradual and/or abrupt.  
   
   
       36 . A method according to  claim 34 , wherein said thermally collapsible holes or voids are wholly or partially collapsed.  
   
   
       37 . A method according to  claim 34 , wherein said heating is being adapted so that a guided mode at said at least one end of the spliceable optical fiber is confined by an index profile determined by background materials of the core and the inner cladding.  
   
   
       38 . A method according to  claim 34 , wherein said heating is provided by a fusion splicer.  
   
   
       39 . A method according to  claim 34 , wherein said coupling comprises fusing of said at least one collapsed spliceable optical fiber end and said optical component.  
   
   
       40 . A method according to  claim 34 , wherein said optical component is an optical fiber, an optical connector, or a combination thereof.  
   
   
       41 . The method according to  claim 40 , wherein said optical fiber is a photonic crystal fiber, or a non-microstructured optical fiber.  
   
   
       42 . The method according to  claim 34 , wherein said collapsing of said thermally collapsible holes or voids is controlled by applying less-than-atmospheric pressure to the holes or voids of the optical fiber to facilitate their collapse.  
   
   
       43 . A spliceable optical fiber for transmission of light in its longitudinal direction, the optical fiber having a cross section perpendicular to the longitudinal direction, said optical fibre comprising 
 (a) a core region; and    (b) a microstructured cladding region, said cladding region surrounding said core region and comprising:    (b1) an inner cladding region with inner cladding features arranged in an inner cladding background material with a refractive index n 1 , said inner cladding features comprising thermally collapsible holes or voids, and    (b2) an outer cladding region with an outer cladding background material with a refractive index n 2 ;    wherein said n 1  being larger than n 2 .    
   
   
       44 . The optical fiber according to  claim 43 , comprising a collapsed section or an end wherein said inner thermally collapsible holes or voids are collapsed.  
   
   
       45 . A optical fiber according to  claim 43 , wherein said inner cladding features have a size of d 1  and said outer cladding region comprises outer cladding features of size d 2 .  
   
   
       46 . An optical fiber according to  claim 45 , wherein d 2  is larger than d 1 .  
   
   
       47 . An optical fiber according to  claim 43 , wherein n 1  and n 2  are different by less than  2 %, such as less than 1%, such as less than 0.5%.  
   
   
       48 . An optical fiber according to  claim 43 , wherein the optical fiber comprises silica-based materials.  
   
   
       49 . An optical fiber according to  claim 43 , wherein said core region comprises a material with a refractive index n core , and n core  is equal to n 1 .  
   
   
       50 . An optical fiber according to  claim 43 , wherein said core region comprises a material with a refractive index n core , and n core  is larger than n 1 .  
   
   
       51 . An optical fiber according to  claim 43 , wherein said core region comprises material with a refractive index n core , and n core  is smaller than n 1 .  
   
   
       52 . An optical fiber according to  claim 43 , wherein said core region comprises a material with a refractive index n core , and n core  is smaller, equal to, or larger than n 2 .  
   
   
       53 . An optical fiber according to  claim 43 , wherein said core region has a diameter smaller than or equal to 3.0 μm.  
   
   
       54 . An optical fiber according to  claim 43 , wherein said optical fiber has at least one position, position 1, along its length where a guided mode at a given wavelength, λ, is confined to the core region by the presence of inner cladding features, and λ is in the range from 0.4 μm to 2.0 μm.  
   
   
       55 . An optical fiber according to  claim 43 , wherein the core region has a largest dimension, r PCF , being in the range of 0.8 μm to 3.0 μm.  
   
   
       56 . An optical fiber according to  claim 43 , wherein the inner cladding region has a largest dimension, r solid , being in the range of 3.0 μm to 15.0 μm.  
   
   
       57 . A preform for producing a spliceable optical fiber as defined in  claim 43 , the preform comprising longitudinal preform elements comprising: 
 (a) at least one core element ( 120 ) comprising a material with refractive index n core ;    (b) inner cladding elements ( 121 ) comprising a tubular element of a material with refractive index n 1 , said tubular element being adapted to form a collapsible hole or void in the spliceable optical fiber; and    (c) outer cladding elements ( 122 ) comprising a material with refractive index n 2 , and wherein n 1  is larger than n 2 .    
   
   
       58 . The preform according to  claim 57 , wherein said tubular element of the inner cladding has an inner dimension d 1,preform  and said outer cladding elements comprising a tubular element with an inner dimension d 2, perform , and d 2, perform , is larger than d1 ,perform .  
   
   
       59 . A method of producing a spliceable optical fiber as defined in  claim 43 , the method comprising drawing an optical fiber from a preform for producing a spliceable optical fiber as defined in  claim 43 , the preform comprising longitudinal preform elements comprising: 
 (a) at least one core element ( 120 ) comprising a material with refractive index n core ;    (b) inner cladding elements ( 121 ) comprising a tubular element of a material with refractive index n 1 , said tubular element being adapted to form a collapsible hole or void in the spliceable optical fiber; and    (c) outer cladding elements ( 122 ) comprising a material with refractive index n 2 , and wherein n 1  is larger than n 2 .    
   
   
       60 . A spliceable optical fiber as defined in  claim 59  obtainable by the method defined in  claim 59 .  
   
   
       61 . A heat-treated spliceable optical fiber comprising a spliceable optical fibre as defined in  claim 59 , or a spliceable optical fiber obtainable by the method defined in  claim 59 , prepared by a heat-treatment of at least one end or a section of the spliceable optical fiber.  
   
   
       62 . An article comprising a spliceable optical fiber for transmission of light in its longitudinal direction, the optical fiber having a cross section perpendicular to the longitudinal direction, said optical fibre comprising: 
 (a) a core region; and    (b) a microstructured cladding region, said cladding region surrounding said core region and comprising:    (b1) an inner cladding region with inner cladding features arranged in an inner cladding background material with a refractive index n 1 , said inner cladding features comprising thermally collapsible holes or voids, and    (b 2 ) an outer cladding region with an outer cladding background material with a refractive index n 2 ;    wherein said n 1  being larger than n 2 , wherein said article is a non-linear fiber component, or a dispersion compensating fiber component.