Interferometric techniques provide inherent depth information.
By imaging the interference pattern generated by a Mirau interferometer as
the reference position is moved, the depth profile of a target structure
can be determined.
Combining this technique with computer microvision allows us to measure the
profile of a target as a function of stimulus phase.
In this image, beam 4 is driven by a sinusoidal voltage while beam 1 is not
The measurements show that the driven beam moves significantly more, but a
small amount of crosstalk causes beam 1 to move slightly.