title: Use of the circular Dammann grating in angle measurement.
abstract: We describe a novel method of angle measurement by borrowing the concept of the circular Dammann grating (CDG). A three-order CDG is employed in this experiment. The displacement of the tilted angle can be determined accurately by measuring the projection from the distorted CDG image. This method is controlled only by the initial radius of the image and the converging ratio of the lens. Compared with conventional techniques, this technique has the advantages of a simple design with superior resolution to within 1 degree, low cost, and compactness. A theoretical analysis together with experimental results is presented.
authors.affiliation: Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong, China.
authors.forename: Fung Jacky
authors.initials: FJ
authors.lastname: Wen
authors.forename: Po Sheun
authors.initials: PS
authors.lastname: Chung