| Popis: |
Fig. 1 graphically illustrates the schematic diagram of vertical scanning interferometry in Michelson interferometer configuration; the light beam from the light source is split into two: one to reference surface and one to measurement surface, then these light beams reflect and interfere with each other. Interference pattern occurs when the optical path difference (OPD) between these two light beams is small, within the coherence length of the light source. The interference pattern is known as interferogram (as shown in Fig. 2), it is recorded by area-based photo-sensitive sensor such as CCD camera. Correlogram is the function of intensity response of each pixel against optical path difference, and it is further processed for height profile measurement. Fig. 3 graphically illustrates correlogram and coherence peak function of vertical scanning interferometry. |
