  The impact of the system design on the control of coupling between planar
waveguide modes and surface plasmon polaritons (SPP) is analyzed. We examine
how the efficiency of the coupling can be enhanced by an appropriate
dimensioning of a multi-layer device structure without using additional
gratings. We demonstrate that by proper design the length of the device can be
dramatically reduced through fabrication a surface plasmon resonance sensor
based on the SPP-photon transformation rather then on SPP dissipation.
