A heterodyne dispersion meter based on total-internal reflection effects and common-path configuration is presented. It is used to measuring the dispersion power of an optical material or component for many applications in industries. The phase difference between S and P-polarizations at the total-internal reflection condition can be extracted and measured accurately by using heterodyne interferometry. The constants of dispersion formulas built by traditional ways could be revised by this method. It has some merits, such as, high resolution and stability, easy to operate, and real-time measurement.
A new method for measuring a very small displacement is presented. The principles of the measurement are based on the critical angle method and confocal technology. It will increase the lateral and longitudinal resolutions higher than 0.3μm and 5nm, respectively, and the maximum displacement could be above 12μm. This optical structure could be applied to measure some messages for optical surface, bio-medical science, and nanotechnology in the future. The new technique has some merits, such as a simple and compact optical setup, high sensitivity, and high resolution.