Rapid modeling and estimation of total spectral loss in optical fibers

The feasibility and practicality of rapid accurate modeling and analysis of the spectral-loss profile of lightguide fibers is demonstrated using an algorithm which applies the method of Marquardt to a single 26-parameter equation containing physically justifiable mathematical models for all known long-wavelength loss mechanisms. The combination of the time-efficient Marquardt regression working in conjunction with a complete total-loss equation obviates the need for multiple data sets, tedious numerical analysis, or expensive, lengthy measurements such as infrared or Raman spectra techniques. The only data required is a single standard cutback loss measurement per fiber examined. The parameter estimates obtained from fitting the 26-parameter model to the loss characteristics of 50 single-mode optical fibers are used to construct a simplified five-parameter loss equation with excellent accuracy. The model is ideally suited for the transmission-performance analysis of lightwave media and systems.