Amplitude-modulated interferometry.
Specific modulating procedures of the interfering amplitudes in a double-beam interferometer lead to highprecision measurements and insensitivity to changes in reflectivity. The performance of such an interferometer is superior to that of a phase-shifting interferometer because the modulated quantity is the amplitude rather than the phase, which is the measured quantity. This system is easier to implement and may be operated faster.
Brunfeld
A
A
Singher
L
L
Shamir
J
J