Process and apparatus for filling microstructured fibers via convection based pressure driven technique

Abstract

A delivery system for filling a microstructured or nanostructured optical fiber (MOF/NOF) includes a MOF/NOF having first and second ends. The first end of the MOF/NOF is disposed in a first chamber configured to have a first pressure, and the second end of the MOF/NOF is disposed in a second chamber configured to have a second pressure that is less than the first pressure. A material source introduces a material into the first chamber. A light source is oriented to emit light into one of the ends of the MOF/NOF. An optical detection system for monitoring filling of the MOF/NOF detects the light emitted by the light source from the other of the ends of the MOF/NOF.

1 . A delivery system for filling a microstructured or nanostructured optical fiber (MOF/NOF), comprising:
 a MOF/NOF having first and second ends, the first end of the MOF/NOF disposed in a first chamber configured to have a first pressure, the second end of the MOF/NOF disposed in a second chamber configured to have a second pressure that is less than the first pressure;   a material source configured to introduce a material into the first chamber;   a light source oriented to emit light into one of the ends of the MOF/NOF; and   an optical detection system for monitoring filling of the MOF/NOF configured to detect the light emitted by the light source from the other of the ends of the MOF/NOF.   
     
     
         2 . The delivery system of  claim 1 , wherein the material source is a gas source and the first chamber is defined by a first gas housing and the second chamber is defined by a second gas housing. 
     
     
         3 . The delivery system of  claim 1 , further comprising a single mode fiber coupling the light source to the one end of the MOF/NOF. 
     
     
         4 . The delivery system of  claim 3 , further comprising a multi-mode fiber coupling the other end of the MOF/NOF to the optical detection system. 
     
     
         5 . The delivery system of  claim 1 , wherein the delivery system is configured as a material sensor, wherein the optical detection system includes an optical spectrum analyzer. 
     
     
         6 . The delivery system of  claim 5 , wherein the MOF/NOF is a photonic bandgap (PBG) fiber and the material source is a gas source. 
     
     
         7 . The delivery system of  claim 1 , wherein the MOF/NOF is a PBG fiber. 
     
     
         8 . The delivery system of clam  1 , wherein the second pressure is atmospheric pressure. 
     
     
         9 . The delivery system of  claim 1 , further comprising a pressure transducer coupled to one of the first or second chambers. 
     
     
         10 . The delivery system of  claim 1 , wherein a difference between the first pressure and the second pressure is sufficient to establish convective flow of the material through the MOF/NOF. 
     
     
         11 . A filling method, comprising:
 providing a microstructured or nanostructured optical fiber (MOF/NOF) having first and second ends;   establishing a pressure difference between the first and second ends of the MOF/NOF, the first end being at a higher pressure than the second end;   introducing a first material to the first end of the MOF/NOF, the pressure difference being sufficient to establish convective flow of the first material toward the second end of the MOF/NOF;   directing light from a light source into the MOF/NOF; and   monitoring filling of the MOF/NOF using detection of the light directed from the light source.   
     
     
         12 . The method of  claim 11 , further comprising performing optical spectrum analysis on the detected light for material analysis. 
     
     
         13 . The method of  claim 11 , wherein the monitoring step includes monitoring absorption of the light transmitted by light source. 
     
     
         14 . The method of  claim 11 , wherein the MOF/NOF fiber is a photonic bandgap (PBG) fiber. 
     
     
         15 . The method of  claim 11 , wherein the light includes a wavelength within the absorption spectrum of the first material. 
     
     
         16 . A gas sensor system, comprising;
 a photonic bandgap (PBG) fiber having a first end disposed within a first chamber and a second end disposed within a second chamber;   a gas source configured to introduce a first gas into one of the chambers;   a light source configured to transmit light into the first end of the PBG fiber, the light having a wavelength within the absorption spectrum of the first gas; and   an optical spectrum analyzer configured to receive the light transmitted by the light source from the second end of the PBG fiber,   wherein the chambers are configured to provide a pressure differential between the first and second ends of the PBG fiber, the pressure differential being sufficient to establish a convective flow of the first gas within the PBG fiber for filling the PBG fiber.   
     
     
         17 . The system of  claim 16 , wherein the light source is a broadband light source. 
     
     
         18 . The system of  claim 16 , wherein a pump is coupled to one of the chambers for establishing, at least in part, the pressure differential. 
     
     
         19 . The system of  claim 16 , wherein a vacuum is coupled to one of the chambers for establishing, at least in part, the pressure differential. 
     
     
         20 . The system of  claim 16 , further comprising a single mode fiber coupling the light source to the first end of the PBG fiber and a multi-mode fiber coupling the second end of the fiber to the optical spectrum analyzer.