Figure 1
Structure diagram of SFRIM.
L is a He-Ne laser, O is the long work distance objective lens, S is the sample, P is the prism, D is the detector and T is the translation stage. ϕ is the apex angle of the prism. XY-plane is horizontal. Central beam of the collimated beam is in YZ-plane and the prism-sample interface is parallel to the XY-plane. The collimated beam out from the laser is focused on the prism-sample interface by the objective lens. Intensity of the reflected light is recorded by linear detector. The computer receives and analyzes data from the detector and controls movement of the translation stages. The enlarged diagram shows the relationship between the detected area and the illuminated spot. IAD is the imager area of the detector. IA is the illuminated area on the sample and CDA is the correspondingly detected area. The spatial resolution of SFRIM is defined as the length on each direction of the detected area, which is Sx along X-axis and Sy along Y-axis.
