FOGALE nanotech’s Low Coherence Interferometric Sensor (LISE) relies on the measurement technique of low coherence interferometry, also referred to as partial coherence interferometry. By comparing the optical paths in the test assembly with the optical path in an internal delay line, the system allows to measure the positions of individual optical elements. All surfaces are detected in one measurement run with a duration of a few tens of seconds. The ”classical“ LISE, well established in industry and research applications, achives an absolute accuracy on airgaps and centre thicknesses of better than ±1 μm over a full measurement range of 400 mm (optical thickness).

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