fbg.prj

A Numerical Photonics library written in C++. The library includes beam propagation method, coupled

begin <fimmwave_prj(1.0)> "FBG"
  begin <FPScanNode(1.0)> "FBG Wavelength Scan"
       "FBG_SMF10" //cdname1
       "REPLICA" //cdname2
       100 //nstep
       1540 1560 //xstart,xend
       "wavelength (nm)" //xlabel
  end
  begin <FPdeviceNode(1.0)> "FBG_period"
    1.55 //lambda
    begin <FPcomponent(1.0)>
      //list of subelement references follow:
      BEGINLIST
      1
      2
      3
      ENDLIST
      //list of subelements follow:
      begin <FPWGsection(1.0)>
        "../SMF10_unexposed" 0.266  // "wgfilename" length
        // LHS rtRegList follows
        begin <RTregionList(1.0)>
          //rCoeff_re rCoeff_im tCoeff_re tCoeff_im xoff yoff xalign yalign shape pars
        
        end
        // RHS rtRegList follows
        begin <RTregionList(1.0)>
          //rCoeff_re rCoeff_im tCoeff_re tCoeff_im xoff yoff xalign yalign shape pars
        
        end
      end
      begin <FPsimpleJoint(1.0)>
        0 0 0 0 0 0 0 0 0 // xoff yoff xalign yalign h_tilt1 v_tilt1 h_tilt2 v_tilt2 method
      end
      begin <FPWGsection(1.0)>
        "../SMF10_exposed" 0.266  // "wgfilename" length
        // LHS rtRegList follows
        begin <RTregionList(1.0)>
          //rCoeff_re rCoeff_im tCoeff_re tCoeff_im xoff yoff xalign yalign shape pars
        
        end
        // RHS rtRegList follows
        begin <RTregionList(1.0)>
          //rCoeff_re rCoeff_im tCoeff_re tCoeff_im xoff yoff xalign yalign shape pars
        
        end
      end
    end
    //lhs input field
    begin <FPInputDefinition(2.0)>
      1 //input type
      1 //single mode input
    end
    //rhs input field
    begin <FPInputDefinition(2.0)>
      1 //input type
      0 //single mode input
    end
  end
  begin <FPdeviceNode(1.0)> "FBG_SMF10"
    1.54 //lambda
    begin <FPcomponent(1.0)>
      //list of subelement references follow:
      BEGINLIST
      1
      2
      3
      4
      5
      ENDLIST
      //list of subelements follow:
      begin <FPWGsection(1.0)>
        "../SMF10_unexposed" 100  // "wgfilename" length
        // LHS rtRegList follows
        begin <RTregionList(1.0)>
          //rCoeff_re rCoeff_im tCoeff_re tCoeff_im xoff yoff xalign yalign shape pars
        
        end
        // RHS rtRegList follows
        begin <RTregionList(1.0)>
          //rCoeff_re rCoeff_im tCoeff_re tCoeff_im xoff yoff xalign yalign shape pars
        
        end
      end
      begin <FPsimpleJoint(1.0)>
        0 0 0 0 0 0 0 0 0 // xoff yoff xalign yalign h_tilt1 v_tilt1 h_tilt2 v_tilt2 method
      end
      begin <FPsimplePeriodic(1.0)>
        1000 "../FBG_period" 0 //nperiod cdsref jointMethod
      end
      begin <FPsimpleJoint(1.0)>
        0 0 0 0 0 0 0 0 0 // xoff yoff xalign yalign h_tilt1 v_tilt1 h_tilt2 v_tilt2 method
      end
      begin <FPWGsection(1.0)>
        "../SMF10_unexposed" 100  // "wgfilename" length
        // LHS rtRegList follows
        begin <RTregionList(1.0)>
          //rCoeff_re rCoeff_im tCoeff_re tCoeff_im xoff yoff xalign yalign shape pars
        
        end
        // RHS rtRegList follows
        begin <RTregionList(1.0)>
          //rCoeff_re rCoeff_im tCoeff_re tCoeff_im xoff yoff xalign yalign shape pars
        
        end
      end
    end
    //lhs input field
    begin <FPInputDefinition(2.0)>
      1 //input type
      1 //single mode input
    end
    //rhs input field
    begin <FPInputDefinition(2.0)>
      1 //input type
      0 //single mode input
    end
  end
  begin <fwguideNode(1.0)> "SMF10_unexposed"
    begin <fwg_wguide(3.0)>
      ""      -1000 
      0               
      1               
      begin <fwg_layers(1.0)>
        //w        nr         alpha      cfseg
        5 1.458 0                        1  
        10 1.455 0                       0  
        METALWALL 0.000000 
      end
    end
    begin <molab_parms(1.0)>
      1 0 0 100 // autoRun <unused> minTEfrac maxTEfrac
      N(1e+50) N(-1e+50)  // evstart evend
      1 0 60 60  // maxNmodes molabOpt nx ny
      1.54 RSGFS 0 1  // lambda solverID solverParms
      // lambda solverID solverParms
    end
  end
  begin <fwguideNode(1.0)> "SMF10_exposed"
    begin <fwg_wguide(3.0)>
      ""      -1000 
      0               
      1               
      begin <fwg_layers(1.0)>
        //w        nr         alpha      cfseg
        5 1.46 0                         1  
        10 1.457 0                       0  
        METALWALL 0.000000 
      end
    end
    begin <molab_parms(1.0)>
      1 0 0 100 // autoRun <unused> minTEfrac maxTEfrac
      N(1e+50) N(-1e+50)  // evstart evend
      1 0 60 60  // maxNmodes molabOpt nx ny
      1.54 RSGFS 0 1  // lambda solverID solverParms
      // lambda solverID solverParms
    end
  end
  begin <notesTB(1.0)> "FBG_Notes"
    >This example illustrates generation of wavelength spectrum for a 
    >Fiber Bragg Grating (FBG). 
    >
    >This example is constructed by first concatenating sections of unexposed and exposed photosensitive fibers 
    >(with core diminsions similar to those of SMF-28) thus creating the FIMMPROP Device "FBG_period." 
    >This Device is then inserted into "FBG_SMF10" as a Simple Periodic Section with 1000 periods, thus creating the 
    >grating structure.
    >
    >To run this example: 
    >- double-click "FBG Wavelength Scan"
    >- Replicate the starting device (FBG in SMF-28 fiber at wavelength 1.54um)
    >- Edit the end device (REPLICA)
    >- Change its wavelength to Lambda=1.56um using Edit/Options
    >- Start/Scan OK and, in approx. 10 seconds on a 1GHz pentium III,
    >a 100-point wavelength scan will appear between 1540nm and 1560nm. 
    >
    >It is clear from the scan that there is minumum transmission around Lambda =1.55um. 
    >
    >To view the intensity profile at this point: 
    >- From the scanner window edit the REPLICA
    >- Change its wavelength to Lambda=1.55um using Edit/Options
    >- View/Optical Field/ XZ Profile OK
    >
    >After a short while the intensity plot will appear, however it is obscured due to the huge discretisation of the 
    >periodic structure, to remove the overlay of the structure from the plot, View/Optical Field/ Toggle Field View. 
    >The reflection should now be obvious. 
    >
    >
    >Note that in this example, delta-n between the core and cladding is kept constant. Thus the mode size does not 
    >oscillate, and only the forward and backward propagating LP01 modes are involved. This suppression of the cladding 
    >modes is why the scan is very fast and accurate.
    > 
    > 
    >Please refer to the document doc\TechNotes\FBG_TechNote.pdf for a more detialed discussion on these Fibre Bragg 
    >Gratings
    >
  end
end