title: Testing the trueness of circular surfaces: a simple holographic method.
abstract: A new holographic method where the object motion or variation is transferred to some other subject (we can call it a probe) is suggested. The theory is developed and verified experimentally for an Ealing precision self-centering lens holder as the probe. The method possesses many advantagesover the conventional holographic interferometry, some of which are (1) the simultaneous presence of four discrete sensitivities to allow a measurable radius change from one to a few hundred wavelengths, (2) comparison of different surfaces without the problem of decorrelation, and (3) no limitation on the light scattering or transmitting capability of the object under study. The limitations of the method are also discussed.
authors.forename: C S
authors.initials: CS
authors.lastname: Vikram
authors.forename: K
authors.initials: K
authors.lastname: Vedam