Effects of Prism Types and Materials on Divergent Beam Illumination and Detection in Surface Plasmon Resonance (SPR) Sensors
J.H. Hossea and J. Widjaja
Kretchsmann-based surface plasmon resonance (SPR) sensors using divergent beam illumination is mathematically analysed by means of geometrical optics. For a given range of refractive index to be measured, our analytical method allows quantitative calculations of optimum beam illumination and detection parameters for equilateral and right-angle prisms of different materials. The analytical results find the importance of a beam incident position on prisms for the sensor optimization. Although a right angle prism with high refractive index has the highest stringent alignment of the beam incident position, it may be suitable for compact SPR sensors because its inclination angle and output beam width are the smallest.
Keywords: Laser diode, Powel lens, geometrical optics, surface plasmon resonance (SPR) sensor, divergent beam illumination, prism apex angle, resonance angle,