Nanofiber spectral analysis

Abstract

Apparatus, systems, and methods may operate to transmit energy to a nanofiber sampling coil and/or a nanofiber reference coil. Further activity may include receiving the energy as modified by evanescent interaction with a sampled material located proximate to the sampling coil and/or as modified by propagation through the reference coil, and comparing the energy modified by evanescent interaction with the energy modified by propagation through the reference coil to determine a spectroscopic property of the sampled material. Additional apparatus, systems, and methods, including the use of nanofibers and fluorescence induced by evanescent radiation to conduct spectroscopic analysis, are disclosed.

1 - 40 . (canceled) 
     
     
         41 . An apparatus, comprising:
 at least one sampling nanofiber formed into a sampling coil having a first sampling end and a second sampling end;   at least one reference nanofiber formed into a reference coil having a first reference end and a second reference end;   a pressure-tight chamber defined by an inner surface that is completely enclosed by an outer surface, the first and the second sampling ends disposed within the chamber, the sampling coil disposed outside the chamber;   an energy source to direct energy to at least one of the first sampling end or the first reference end; and   a receiver to receive at least one of the energy modified by evanescent interaction with a sampled material located within an inner diameter of the sampling coil or outside an outer diameter of the sampling coil, or the energy modified by propagation through the reference coil.   
     
     
         42 . The apparatus of  claim 41 , wherein the energy source comprises:
 a plurality of broadband sources having substantially orthogonal wave functions, wherein the energy comprises a corresponding plurality of energies directed to a corresponding plurality of sampling nanofibers that include the sampling nanofiber.   
     
     
         43 . The apparatus of  claim 42 , wherein the plurality of energies is directed to a corresponding plurality of reference nanofibers that include the reference nanofiber. 
     
     
         44 . The apparatus of  claim 41 , wherein the energy source comprises a broadband Page  4  energy source, and wherein the receiver comprises:
 one of a tunable receiver to resolve a plurality of wavelengths in the energy provided by the broadband energy source or a plurality of receivers corresponding to a plurality of reception wavelength sensitivities. 
 
     
     
         45 . The apparatus of  claim 41 , wherein the energy source comprises:
 one of a single broadband source or a plurality of substantially monochromatic sources to provide the energy, wherein the energy comprises a corresponding plurality of energies directed to a corresponding plurality of sampling nanofibers that include the sampling nanofiber.   
     
     
         46 . The apparatus of  claim 41 , wherein the energy source comprises:
 one of a broadband source or a substantially monochromatic source.   
     
     
         47 . The apparatus of  claim 41 , wherein the energy sources comprises:
 a frequency tunable, substantially monochromatic source.   
     
     
         48 . The apparatus of  claim 41 , wherein the reference coil is disposed outside the chamber. 
     
     
         49 . The apparatus of  claim 41 , further comprising:
 a plurality of sampling nanofibers, including the sampling nanofiber, formed into a corresponding plurality of sampling coils, at least two of the plurality of sampling coils having different coil diameters corresponding to different sensitivity wavelengths, and a spacing between loops in the at least two of the plurality of coils greater than one evanescent wavelength associated with one of the at least two of the plurality of coils.   
     
     
         50 . The apparatus of  claim 41 , wherein the sampling coil is at least partially coated with a pH-selective compound or an ion-selective compound. 
     
     
         51 . A system, comprising:
 at least one sampling nanofiber formed into a sampling coil having a first sampling end and a second sampling end;   at least one reference nanofiber formed into a reference coil having a first reference end and a second reference end;   a pressure-tight chamber defined by an inner surface that is completely enclosed by an outer surface, the first and the second sampling ends disposed within the chamber, the sampling coil disposed outside the chamber;   an energy source to direct energy to at least one of the first sampling end or the first reference end;   a receiver to receive at least one of the energy modified by evanescent interaction with a sampled material located within an inner diameter of the sampling coil or outside an outer diameter of the sampling coil, or the energy modified by propagation through the reference coil; and   a downhole tool attached to the energy source, the receiver, and the chamber.   
     
     
         52 . The system of  claim 51 , further comprising:
 a balancing bridge coupled to the sampling nanofiber and the reference nanofiber.   
     
     
         53 . The system of  claim 51 , further comprising:
 a response regression module to receive a receiver output signal from the receiver and to provide a regression output based on a calibration input and the receiver output.   
     
     
         54 . The system of  claim 51 , further comprising:
 a wavelength discriminator interposed between the second sampling end and the receiver.   
     
     
         55 . The system of  claim 51 , wherein the energy source comprises:
 a plurality of energy sources coupled to a multiple-input, single-output multiplexer.   
     
     
         56 . The system of  claim 51 , further comprising:
 a ferromagnetic seal to seal the sampling nanofiber against the inner surface.   
     
     
         57 . A method, comprising:
 transmitting energy to at least one of a first sampling end of a nanofiber sampling coil having a second sampling end, or a first reference end of a nanofiber reference coil having a second reference end;   receiving at least one of the energy modified by evanescent interaction with a sampled material located within an inner diameter or outside of an outer diameter of the sampling coil, or the energy modified by propagation through the reference coil; and   comparing the energy modified by evanescent interaction with the energy modified by propagation through the reference coil to determine a spectroscopic property of the sampled material.   
     
     
         58 . The method of  claim 57 , further comprising:
 publishing a material property or a chemical property of the sampled material based on the spectroscopic property.   
     
     
         59 . The method of  claim 57 , further comprising:
 immersing the sampling coil in a downhole fluid located outside a pressure-tight chamber housing an energy source used to provide the energy during the transmitting.   
     
     
         60 . The method of  claim 57 , wherein the receiving further comprises:
 multiplexing reception through a plurality of sampling coils, including the sampling coil, wherein at least two of the plurality of sampling coils have different coil diameters.