Resonant interaction between two core modes in a plasmonic biosensor based on a birefringent solid-core microstructured optical fiber

By using a finite element method with matched boundary conditions, we analyze an interaction between a central core mode (x- and y- polarizations), which shows as a supermode and a plasmonic mode by involvement of another (lateral) core mode in a biosensor based on a birefringent solid-core microstructured optical fiber. The transmission losses of the lateral core modes are larger than those of the corresponding central core modes for the x- and y- polarization components. A very interesting result is that the maximum value of the amplitude sensitivity for the second (lateral) core (II, x) mode (x- polarization) is at a wavelength close to the resonant wavelength of the first (central) core (I, x) mode. Also, the maximum value of the amplitude sensitivity for the second core (II, y) mode (y- polarization) is at a wavelength that is close to the resonant wavelength of the first core (I, y) mode. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement