Meaning
Sub-nanometre topography scanning uses light phase interference to map the surface profile of a sample. During white-light interferometry, a split beam hits both a reference mirror and the item surface to look for height differences through interference fringes. This non-invasive method works across a wide variety of materials from mirror-finished metals to rough plastic parts.
Height Resolution
Precision is reached when the instrument is isolated from floor vibrations that could blur the light patterns. Because white-light interferometry reads vertical changes at the scale of wavelengths, it remains the standard for detecting the slightest variations in optic flatness. Maps are produced in three dimensions with incredible vertical detail.
Measurement Range
Breadth is limited by the distance the scanner can move its focal plane vertically without losing signal. Utilizing white-light interferometry enables the detection of defects in semiconductor chips or micro-gears that visual inspection would easily skip. It provides numerical values for roughness that tactile probes are too clumsy to resolve.
Quality Verification
Compliance is verified by checking scanned batches against high precision flatness standards. Integrating white-light interferometry into high-end labs reduces the time spent on manual adjustments. It offers a clear defensible image of the finished surface finish for every critical item.
