Applied Physics B

, Volume 79, Issue 1, pp 51-55

First online:

Study of ultra-fast optical pulse propagation in a nonlinear directional coupler

  • Y. WangAffiliated withOptical Fiber Department, Agilent Technologies Singapore Pte. Ltd. Email author 
  • , W. WangAffiliated withDivision of Physics and Astronomy, Vrije University Amsterdam

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We showed that the application of a soliton in a nonlinear coupler does not show a better switching performance than a Gaussian pulse, unlike what the existing theory expected. Like the Gaussian pulse, a soliton could also suffer distortion, broadening, or narrowing in a nonlinear directional coupler. In addition, by using a new normalized format the linearly coupled nonlinear Schrödinger equations were investigated. For the first time, we found that both the coupling behavior and the switching performance of pulses in a nonlinear coupler depend on the product of the coupling coefficient and the dispersion length. We also showed that for a given nonlinear coupler with a Gaussian-like or soliton-like pulse input, switching performance and whether a pulse breaks up or not mainly depend on the input pulse width, not the pulse shape.