Four-beam laser interferometry for three-dimensional microscopic coordinate measurement.
We propose a new method for calibrating the three-dimensional (3-D) behavior of a scanning stage. Four laser interferometers are used to determine the position of the corner point of a corner mirror attached to the stage. We calculated the 3-D coordinate of the corner point by using only the length information given by the four laser interferometers; thus a method is realized that is traceable from the practical definition of length and that facilitates the optical alignment that is necessary for the interferometers. We calibrated a commercial 3-D stage by the proposed method with a coordinate accuracy of 20-30 nm.
Linear interpolation of periodic error in a heterodyne laser interferometer at subnanometer levels (dimension measurement)
Heterodyne laser interferometry and its accuracy at subnanometer levels are discussed. The simplest optical nonpolarization heterodyne interferometer is tested experimentally to understand and reduce fringe distortion. An accuracy of 0.1 nm for the 633-nm He-Ne laser interferometer is achieved. >
Chemical Metallurgy: Principles and Practice
Foreword. Preface. Acknowledgements. Appreciation. 1. Acquaintance. 2. Mineral Processing. 3. Thermodynamics and Kinetics. 4. Pyrometallurgy. 5. Hydrometallurgy. 6. Electrometallurgy. 7. Energy and Environment. Subject Index.