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This paper makes use of the unambiguous definitions of angles of incidence and refraction offered by the author in 2005 to make an extensive study of the theoretical behavior of the (i – δ) curve of a prism in ray optics. Novel relations have been achieved for the explicit dependence of the final angle of emergence (i2) as well as the net deviation (δ) on the unambiguous primary angle of incidence (i1). Considering a glass prism with angle, A = 60° and refractive index, μ = 1.5, the theoretical relations developed have been subsequently employed to predict the graphical behavior of each of the (i1 versus i2) curve, (i1 versus (i2 − i1)) curve, and (i1 versus δ) curve. Though the quantitative interpretation of the peculiar nature of the (i1 versus δ) curve of a prism follows from the relevant relation derived in the paper, qualitative interpretation regarding the peculiar trend of variation of the net deviation (δ) with the unambiguous primary angle of incidence (i1) has also been provided on the basis of the (i1 versus i2) as well as (i1 versus (i2 − i1)) curves.

This letter demonstrates a technique that utilizes the camera of a smartphone for evanescent wave coupled spectroscopic sensing. Using simple optical components, the camera of the smartphone is converted into a highly resolved spectrometer (0.305 nm per pixel), and using a right-angled glass prism, the evanescent field of the internally reflected light signal from a broadband optical source is allowed to interact with the external medium. The primary advantages of the proposed sensing technique are its compactness, portability, and cost-efficiency.

The discrete sources method is extended to analyse evanescent waves scattering by a non-spherical particle located near a metal-coated glass prism. A metallic film is designed to enhance conversion of an evanescent wave into a scattered one via computational simulations. The importance of taking into account interaction between scatterer and multi-layered interface is demonstrated.

In this work, we have proposed a novel long-range surface plasmon resonance (LRSPR) sensor with sharp reflection spectrum, which consists of a glass prism, a (A/B)4-type waveguide-coupled layer and a metal layer. To reveal its sharp reflection spectrum perfectly, we have simulated the effects of all factors of this LRSPR sensor on the reflection spectrum, and finally presented the optimal parameters of the LRSPR sensor with sharp reflection spectrum.

Anyone who has looked at a rainbow has surely found them to be interesting and beautiful. For a long time few people understood what they saw. It was Sir Isaac Newton (1642–1727) who demonstrated what causes rainbows and some of the deeper characteristics of light. Newton took a glass prism and allowed a sliver (light through a small slit) of light to fall on it. What was seen on the other side of the prism was a rainbow of colors. White light was broken down into rainbow colors (Fig. 1.1).

An experimental setup is described which uses a prismatic dye cuvette and a dispersion glass prism. The two prisms are oriented so as to ensure wavelength-dependent deflection in two perpendicular planes. The dispersion of the solvent material was subtracted by using an immersion cuvette filled with the solvent liquid of the dye solution. The setup displays the contribution of the dye material to the refractive index of the solution as a function of the wavelength. The setup is simple, inexpensive, does not use toxic or hazardous materials or high temperature ovens, and thus can be a very useful means to demonstrate the effect of anomalous dispersion at different levels of education.

Optics and refraction are often thought of as a dry chapter in ophthalmology, but understanding a few basic principles enables one to avoid errors and complications when treating both pediatric and adult strabismic patients.

Ultra-violet rays were discovered as long ago as 1800, but it is only comparatively recently that people, other than scientists, have taken much interest in them. But to get back to the beginning of the subject one has to go back as far as 1666, when Isaac Newton made his famous experiment. He let a beam of sunlight pass through a glass prism and found that this beam was apparently split into a lot of different rays, which are now known as the spectral colours. Newton's experiment may be arranged so that the rays emerging from the prism fall on a white screen, and the band of different coloured lights, ranging from red at one end to violet at the other, can be carefully examined. Between the red and violet are the bands of orange, yellow, green, blue and indigo. There is no definite point where the violet light stops, as some people can see a little further than others in the region of light, but no one can see any colour beyond a certain limit, and this is where the ultra-violet rays begin. These rays ar...

Light of many colours can be derived from white light, e.g. from sunlight. A band of colours or a rainbow appears when direct sunlight is refracted by raindrops in the sky; and a similar band of colours is produced when a ray of white light from a tungsten filament lamp is refracted on passing through a triangular glass prism (Fig. 18.1). The band of colours displayed on the white screen is called a spectrum. It is not a pure spectrum, however, as some of the colours in the middle of the band overlap one another.

I WAS led the other day to consider the possible effect of changes of barometric pressure on the ultimate destination of light passing through lighthouse refracting agents, and although I was satisfied that such changes cannot produce any effects of practical importance, the idea occurred to me that a glass prism might be used as a barometer. When a refracting prism is successively immersed in media of different refractive indices the ultimate angular deviation of the ray will, as is well known, depend in each case on the relative indices of the glass and the medium surrounding it at the time of the experiment. And as the refractive index of atmospheric air varies with its density, the amount of deviation of the refracted ray will be a measure of the density of the air, i.e. will give the means of ascertaining the reading of the barometer at the time.

Infrared radiation was first observed by William Herschel in 1800. Using a glass prism and thermometers, he found that there were two maxima, one occurring in the yellow-green portion of the sun’s spectrum and the other beyond the red end of the visible spectrum. He mistakenly believed that these maxima were due to two different types of radiation. Between 1835 and 1845, it was postulated and generally accepted that these maxima were actually similar phenomena, differing only in the amount of refraction by the prism.