Immersion Mirau Interferometer
An immersion Mirau interferometer is a modification of a Mirau interferometer, in which the light path is immersed in a liquid medium. One application of an immersion Mirau interferometer is to image cells with medium. Since the index of refraction of the medium is substantially different from that of the neighboring air, each millimeter of medium would introduce a path length difference from the reference wave, and ideal interference conditions are lost. Filling the microscope optics with medium restores the ideal interference conditions.
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