Wavelength And Angle Modulation Spr Detection Technology

Surface Plasmon Resonance (SPR for short) is a complicated physical optics phenomenon. SPR technique has capacious application foreground because of its advantages of real time monitor, no label, high selectivity, no interruption of background.The principle of SPR is that when P-polarized light occurs total internal reflection at the interface of transmission medium and metal surface, the evanescent wave that penetrates to metal film excitatedes surface plasmon oscillation of free electron in metal. Surface plasmon resonance happens when the wave vector of surface plasmon wave equals to the wave vector component of incident light in metal tangential direction.This thesis researches angle and wavelength interrogation together detection technology based on prism couplers. The center wavelength of light source is 840nm, and its bandwidth is 50nm. When incident light run by some angle, finding out resonant wavelength of atmosphere medium, changing incident angle, the wavelength also changes. The paper has three different incident angles, respectively finding out corresponding absorption spectrum and resonant wavelength, and the changing direction of wavelength in experiment coincides with theory.