Reflection of light by a convex Fresnel lens gives rise to two distinct images. A highly convex inverted real reflective image forms on the object side of the lens, while an upright virtual reflective image forms on the opposite side of the lens. I describe here a set of laser experiments performed upon a Fresnel lens. These experiments provide…

To help students develop an understanding of the proper use and function of spectrographs and monochromators we describe a student-assembled spectrograph using a "webcam" detector. The apparatus also works well as a low-cost demonstration, helping students make connections between an atomic spectrum observed by eye and a plot of the relative…

Applications of a simple approximation of Bessel functions of integer order, in terms of trigonometric functions, are discussed for several examples from electromagnetism and optics. The method may be applied in the intermediate regime, bridging the "small values regime" and the "asymptotic" one, and covering, in this way, an area of great…

This article reports a design experiment conducted over three successive school years, with the teacher's goal of having his Grade 4 students assume increasing levels of collective responsibility for advancing their knowledge of optics. Classroom practices conducive to sustained knowledge building were co-constructed by the teacher and students,…

Several papers have been published on the use of a CD as a grating for undergraduate laboratories and/or for high school and college class demonstrations. Four years ago "The Physics Teacher" had a spectacular cover picture showing emission spectrum as viewed through a CD with no coating. That picture gave the impetus to develop a system that can…

Many science topics can naturally be integrated with a variety of mathematical concepts, including the study of light and optics. In the hands-on activities described here, students explore the properties of light energy while building their understanding of geometric concepts. (Contains 2 figures.)

Explains the asymmetry between left-right and up-down when your image is viewed in a plane mirror in psychological rather than physical terms. (GS)

Discusses developments in the field of gradient index optical lenses for resolving problems of lens spherical abberration. (SL)

Discusses the optics of fly fishing, considering where to cast the fly once a fish is seen. Also considers what the fisherman looks like to the fish, examining refraction at a water surface, actual and apparent light rays, and how sticks in the water might look to a fish. (JN)