An optical fiber containing one or more random modulations capable of
reflecting one or more random wavelengths of light passing through the
optical fiber is provided. Each modulation is a section of the optical
fiber in which the refractive index has been modified or a section of
random refractive index optical fiber that has been spliced into the
optical fiber. The optical fiber is produced by modifying the refractive
index of at least one portion of the optical fiber through photo-etching,
photo-bleaching, ultraviolet radiation exposure or splicing. The optical
fiber containing the random modulation is used to measure one or more
engineering parameters by locating the section or portion of the optical
fiber containing the random modulation in an area where the engineering
parameter is to be measured and measuring the engineering parameter using
optical frequency domain reflectometry.