The Swift Turbidity Marker is an optical instrument developed to measure the level of water turbidity. The components and configuration selected for the system are based on common turbidity meter design concepts but use a simplified methodology to produce rapid turbidity measurements. This work is aimed at high school physics students and is the…

Mathematically analyzes the polarization of rainbows, a phenomenon which can be demonstrated in a laboratory simulation using polaroid sheets, perspex discs, and a white light source. (MLH)

Describes an apparatus which attempts to give a direct visual impression of the random detection of individual photons coupled with the recognition of the classical intensity distribution as a result of fairly high proton statistics. (Author/GA)

Explains magneto-optical effects and describes techniques which may be used, in conjunction with certain materials, to reveal domain structures. In addition, simple experiments are described which enable domains to be observed under various conditions of applied fields. (Author/GA)

Describes how to construct a simple on-axis hologram designed to illustrate the reconstruction of images in terms of Fresnel zone plates and gratings. (GA)

Explains how to construct a three dimensional model for stereographic projection. It will be suitable for presenting the symmetry of crystal systems, and will help physics students understand the nature of crystallography. (GA)

Using the simple optical system and photodiode described in this article it is possible to give clear, quantitative demonstrations of all the Fraunhofer diffraction phenomena at single and multiple apertures. These measurements can be related to the theoretical predictions given in standard textbooks. Circuit diagram and optical layout are…

Describes a simple experiment to verify the reflectivity equations of Fresnel and for measurement of optical constants. (SL)

Presents two methods used to measure the refractive indices and double-refraction of fibers. Experiments are described, with one involving the use of Pluta microscope in the double-beam interference technique, the other employing the multiple-beam technique. Immersion liquids are discussed that can be used in the experiments. (TW)

Describes a solid etalon Fabry-Perot interferometer, discussing free spectral range, instrumental finesse, and temperature effects. Provides schematic of temperature control/display circuit. Explains use of 100 millimeter camera lens and 10 power micrometer eyepiece for resolving rings and measure diameters. (JM)

Describes use of a Fresnel biprism to demonstrate double-slit interference with polarized light. Discusses polarization and phase properties of a randomly polarized gas. (JM)

Describes (1) computer graphics for the coefficient of restitution; (2) an experiment on the optical processing of images; and (3) a simple, coherent optical system for character recognition using Polaroid (Type 665) negative film. (JN)

Suggests experiments to help develop understanding of photoconductivity, photometry, and the inverse square law in optics. The design of a simple absorption colorimeter is also described. (DH)

Suggests a method treating geometric optics using a microcomputer to do the calculations of image formation. Calculations are based on the connection between the composition of lenses and the mathematics of fractional linear equations. Logic of the analysis and an example problem are included. (JM)

Describes apparatus needed and instructions for conducting four experiments. Experiments focus on light waves, measurement of contact resistance, demonstration of longitudinal waves, and a simple method of measuring the refractive indices of transparent plates and liquids. (JM)