The collimated laser projected onto a ceiling through the Olympus 100x 1.45NA TIRF objective:
This beam is then steered to the critical angle by scanning the focused beam across the back aperture of the objective lens:
At the critical angle the return beam is seen:
It is now possible to image some fluorescent beads (20nm diameter), this image was taken using a £70 Security CCD camera from the local electronics store! This is a shot of the monitor, because the camera output is analogue and I don't have a video card.... Incredible huh?!
