The test system concept is shown in the figure above. The light source is exchangeable from a low coherent source (e.g. LED) to a laser source (e.g. laser diode). The requirements to the laser source are rather low due to the short optical path length difference in the interferometer arms (typical<500µm).

Illumination, probing and imaging wafer are all exchangeable. The M(O)EMS wafer is mounted and positioned using a wafer handling and positioning system available in commerce.

The interferometers are placed in a regular 5x5 array. Each interferometer channel has its own light source and is separated to avoid cross talk. Also the camera is devided into a distributed 5x5 array containing 140x140 smart pixels each.