text: in the following detailed description , reference is made accompanying drawings that illustrate embodiments of the present invention . these embodiments are described in sufficient detail to enable a person of ordinary skill in the art to practice the invention without undue experimentation . it should be understood , however , that the embodiments and examples described herein are given by way of illustration only , and not by way of limitation . various substitutions , modifications , additions , and rearrangements may be made without departing from the spirit of the present invention . therefore , the description that follows is not to be taken in a limited sense , and the scope of the present invention is defined only by the appended claims . fig1 illustrates a conventional dts system , including a light source 10 , a lead light fiber 11 , a light splitter and combiner 12 , lead fiber 13 , a sensing fiber 14 , optical spectrum separator 16 , and a reference fiber coil 22 . light source 10 provides optical signal through lead fiber 11 which may reach sensing fiber 14 via light splitter / combiner 12 , reference fiber coil 22 , and lead fiber 13 . during the transmission of optical signal to sensing fiber 14 , a portion of the light may be scattered and may travel back to optical spectrum separator 16 via lead fiber 13 and light splitter / combiner 12 , and fiber 15 . the backscattered light from the sensing fiber may include light components such as rayleigh component 17 ( same center wavelength as injected light ), brillouin stokes component 18 and brillouin anti - stokes component 19 , raman stokes component 20 , and raman anti - stokes component 21 , all of which may be separated via optical spectrum separator 16 . raman stokes 20 and raman anti - stokes 21 ( collected raman scatterings ) may be shifted from the input wavelength of the optical signal and be mirror imaged about rayleigh component 17 , as shown in fig2 . reference fiber coil 22 of the dts system may be used as a reference profile for the entire temperature profile of the sensing fiber . for other profiles , reference fiber coil 22 may be used as a reference point to compare or analyze measured points . in one embodiment , the raman components may be used to determine parameter profiles such as temperature profiles . the raman stokes and raman anti - stokes band are typically separated by more than tens of nanometers , whereas brillouin components 18 and 19 are much closer — less than 0 . 1 nanometer from the rayleigh bandwidth , as shown in fig2 . in particular , the temperature may be inversely proportional to the intensity of raman stokes component 20 over the intensity of raman anti - stokes component 21 . fig3 , shown generally as the numeral 100 , shows a block diagram of an embodiment of the inventive concept . in this embodiment the laser source 110 is fed into a fiber optic cable and a photonic crystal fiber ( pcf ) 120 is placed along the laser path to act as a broadening catalyst . photonic fiber crystals are a class of optical fibers based on photonic crystals . the highly non - linear optical effects of pcf &# 39 ; s result in a broadening of the spectrum of the laser reducing coherence and as a result mitigate coherent rayleigh scattering ( crs ). some of the non - linear responses include modulation instability , self modulation , stimulated raman scattering , and four wave mixing . the combination of these effects in complementary and competing fashions result in a broader line width spectrum . a broader line width reduces coherence and therefor reduces crs . the resulting broadened signal is then sent into an attenuator system 130 and then fed into a wavelength division multiplexer ( wmd ) 140 before feeding into the a dts system . fig4 , shown generally as the numeral 200 , shows an alternate embodiment for broadening the spectrum of a laser source . in this embodiment a primary laser source 210 still feeds through a photonic crystal fiber 230 . in this second embodiment a second high power seed laser source 250 is added . this second laser source , operates in a continuous wave mode and counter propagates through the photonic crystal fiber along with the primary source . second laser source 250 is combined with the other laser source in a wavelength division multiplexer 240 , then feeds into an attenuator system 260 before feeding into a dts system . a seed source wavelength block 220 is provided to prevent the seed source wavelength from entering primary source 210 . fig5 , shown generally as the numeral 300 , now demonstrates a typical effect of the spectral broadening configurations of either the embodiment of fig3 or the embodiment of fig4 . the plot is of the signal strength of backscattered rayleigh laser signal versus distance ( in meters ) in an extended dts sensing system . curve 320 is a backscattered rayleigh signal from a normal dts system , exhibiting the typical noise envelope surrounding a backscattered rayleigh signal in longer distance applications . this noise envelope can reduce the performance of any system attempting to use the rayleigh backscattered signal for measurement or calibration . curve 310 represents a backscattered rayleigh signal resulting from the reduction in coherent rayleigh scattering possible from either of the proposed spectral broadening schemes . modern dual laser raman dts calculation methods , such as described in u . s . pat . no . 7 , 628 , 531 or u . s . publication 201010128756a1 offer a new capability to self correct for dynamically changing differences in signal attenuation that can result from fiber damage during and after installation as well as losses from hydrogen ingression . these are prevalent in oil and gas application . but when seeking higher power , greater distance , and higher resolution it often becomes necessary to collect the rayleigh signal as part of the dts calculation routine . with the ability described here for reducing the noise contribution from the rayleigh signal it now will be possible to create dts systems with unsurpassed reach ( distance ) and resolution with the addition of self correcting for difference in attenuation in harsh environments . although certain embodiments of the present invention and their advantages have been described herein in detail , it should be understood that various changes , substitutions and alterations can be made without departing from the spirit and scope of the invention as defined by the appended claims . moreover , the scope of the present invention is not intended to be limited to the particular embodiments of the processes , machines , manufactures , means , methods and steps described herein . as a person of ordinary skill in the art will readily appreciate from this disclosure , other processes , machines , manufactures , means , methods , or steps , presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention . accordingly , the appended claims are intended to include within their scope such processes , machines , manufactures , means , methods or steps .