In order to perform surface measurement, the beam is expanded to be adjusted to the size of the area of interest. The surface under test is imaged onto the SID4 wavefront sensor. First, a reference measurement is performed with a reference flat and the test sample is aligned and measured. The measured wavefront is twice the topography of the test surface.
Advantages
Complete and accurate
- Instantaneous complete 3D shape
- High dynamic range
- High-resolution map
Ease of use and versatility
- No CHG or null lens
- No stitching / scanning
- Non-contact measurement
Common-path interferometry
- No reference arm
- Insensitive to vibrations
- Easy alignment