Interferometers eliminate test plates during fabrication

This article discusses the typical method of testing optical components during fabrication is with test plates.

Mar 17, 1998

Optical properties of alumina titanium carbide sliders used in rigid disk drives

In this article, the author derives the effective complex reflectivity of this material, using scalar diffraction theory and the known indices of refraction of Al2O3 and TiC. The effective reflectivity is a function of the relative surface area of the exposed TiC grains as well as of the numerical aperture of the collection optics.

Jan 1, 1998

Determining the optical constants of read-write sliders during flying-height testing

Authors describe an instrument that determines the optical constants simultaneously with flying height, using polarization interferometry. This in situ analysis of n and k obviates the need for independent ellipsometry, while avoiding the problematic retract calibration characteristic of traditional flying-height test equipment.

Jan 1, 1998

Punctuated quadrature phase-shifting interferometry

In this article, authors describe a method and algorithm for reducing the sensitivity of phase-shifting interferometry to external vibrations.

Jan 1, 1998

Birefringence in rapidly rotating glass disks

This article discusses how centripetal forces modify the optical properties of a rotating glass disk, thus creating a circularly symmetric distortion in the refractive index.

Nov 7, 1997

101-frame algorithm for phase-shifting interferometry

This paper explores the limits of these trends, while reviewing some of the mathematical techniques that we at Zygo use to analyze PSI performance. Finally, in an attempt to predict far into the future, the author presents a 101-frame algorithm that is highly resistant to error sources. This somewhat extreme example highlights the practical limits on algorithm length, which are actually more relaxed than one might think, provided that we loosen the definition of PSI.

Sep 17, 1997

Vibration-resistant phase-shifting interferometry

This article discusses a method to reduce the sensitivity of phase-shifting interferometry to external vibrations.

Dec 1, 1996

Interferometric analysis of stress-induced birefringence in a rotating glass disk

In this article, the authors provide a model for stress-induced polarization effects, and describe an interferometric technique for mapping birefringence in a 100-nm diameter disk spinning at 12,000 rpm.

Jun 30, 1996

Numerical simulations of vibration in phase-shifting interferometry

This article discusses how computer simulations predict the expected rms measurement error in a phase-shifting interferometer in the presence of mechanical vibrations.

May 1, 1996

Grating interferometer for flatness testing

This article discusses how two diffraction gratings placed in front of a flat surface generate an interference pattern representing the surface deformations.

Feb 1, 1996

Polarization interferometer for measuring the flying height of magnetic read–write heads

Authors propose a tester that fully analyzes the complex amplitude reflectivity of the interface, including the polarization-dependent complex phase.

Aug 30, 1995

Derivation of algorithms for phase-shifting interferometry using the concept of a data-sampling window

In this article, the author proposes a systematic way to derive efficient, error-compensating algorithms for phase-shifting interferometry by integer approximation of well-known data-sampling windows.

Aug 1, 1995