Robert H. Katyl

Compensating Optical Systems. Part 3: Achromatic Fourier Transformation

This paper shows the requirements for the achromatization of an irradiance distribution which is a function of a space coordinate multiplied by wavelength raised to a power. The particular requirements for achromatic Fourier transformation are then presented. The theory is applied to the following problems: achromatization of Newtons ring patterns and Fraunhofer diffraction patterns and frequency plane. filtering of an object illuminated with a broadband light source. Experimental systems that perform these functions are presented.

Compensating Optical Systems. Part1: Broadband Holographic Reconstruction

The primary chromatic aberrations of a reconstructed holographic image can be compensated by a dispersive lens placed at the quasi-achromatic (QA) point of a hologram. The conditions for obtaining this compensation are derived. Three experimental systems that employ this compensation are discussed. Two of these are in line and use either a zone plate lens or flint glass lens as the dispersive element centered at the QA point. In the third system, an off-axis hologram is followed by an off-axis zone plate lens positioned at the offset QA point.

Mass transfer of an impinging jet confined between parallel plates

An understanding of the mass transfer behavior of an impinging jet can be usefully applied to wet chemical processes such as water rinsing, photoresist development, and metal etching or plating. Theoretical and experimental methods were used to study the mass transfer characteristics of an axisymmetric impinging jet confined between two parallel plates. Such a configuration was used because of its potential applicability to the fabrication of printed wiring boards. The CFD (computational fluid dynamics) method was used to model fluid flow and mass transfer. An electrochemical probe based on the ferro-ferricyanide system was used to experimentally determine the mass transfer coefficients and to evaluate the applicability of the theoretical methods used. An etching method was used to characterize the mass transfer rates in a typical cupric chloride etching solution. A new observation of the effect of jet instability on the etching rate in the central impingement zone is discussed.

Moiré Screens Coded with Pseudo-Random Sequences

A new type of moiré grating that can produce very narrow moiré beat lines is presented. Each grating period contains a number of transparent or opaque lines of equal width. The sequence of transmission coefficients across the grating period is not periodic but is chosen to be a binary pseudo-random sequence. These sequences are commonly used in signal processing because of their sharply peaked autocorrelations. When used to encode a moiré grating, they produce very narrow moiré beat lines. Three experimental gratings are discussed, and a contouring measurement using the narrow beat lines is described.

Compensating Optical Systems. Part 2: Generation of Holograms with Broadband Light

A technique is presented for recording Fresnel holograms with a broad spectral bandwidth light source. The conditions for obtaining an achromatic Fresnel diffraction pattern at the hologram plane are derived, and aberrations resulting from approximate compensation are discussed. Three experimental compensating systems are presented.