Impact of high index buffer layer on the improvement of the MMI sensor sensitivity


  • Artur Szewczuk
  • Marek Błahut



The results of investigations of the impact of high index buffer layer on the improvement of the multimode interference (MMI) sensor sensitivity are presented. The basis of the presented research is a gradient index MMI structure with multimode section length relating to the length of the input field image formation. Multimode section is covered with material which changes its optical parameters (refractive index and extinction coefficient) when is exposed to appropriate gaseous environments. The coating parameters changes effect on light propagation condition in structure which can be seen as the output signal variation. In this configuration a thin buffer layer of high refractive index is placed between the sensing layer and a gradient core. We present results showing how these buffer layers lead to an increase of sensitivity of the sensor based on the MMI structures. Performed analysis are based on the numerical BPM calculation.

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How to Cite

A. Szewczuk and M. Błahut, “Impact of high index buffer layer on the improvement of the MMI sensor sensitivity”, Photonics Lett. Pol., vol. 6, no. 4, pp. pp. 127–129, Dec. 2014.