# Incident light sentence example

incident light

- Fluorescence and Constitution.-The physical investigation of the phenomenon named fluorescence-the property of transforming incident light into light of different refrangibilityis treated in the article Fluorescence.
- der Phys., 1900, p. 352); they express the percentage of incident light reflected.
- Such bodies are said to be fluorescent, the degradation of motion towards that determined by its temperature gives rise to the law of Stokes, the fluorescent light being in nearly all cases of lower frequency than the incident light.
- It is closely related to the coefficient k which we have just defined, the equation connecting the two being k= 4lrK/X,X being the wavelength of the incident light.
- This was supplied by Fresnel, who, starting from a mechanical hypothesis, showed by ingenious but not strictly dynamical reasoning that if the incident stream have unit amplitude, that of the reflected stream will be - sin (i - r) /sin (i -{- r) or tan (i - r) /tan (i -{- r), according as the incident light is polarized in or perpendicularly to the plane of incidence i, r, being the angles of incidence and refraction connected by the formula sin i =,u sin r.Advertisement
- If the incident light be polarized in a plane, making an angle a with the plane of incidence, the stream may be resolved into two that are polarized in the principal azimuths, and these will be reflected in accordance with the above laws.
- Applying this interpretation to the formulae given above, it follows that when the incident light is polarized at an azimuth a to the plane of incidence and the second medium is the less refracting, the reflected light at angles of incidence exceeding the critical angle is elliptically polarized with a difference of phase A between the components polarized in the principal azimuths that is given by tan (A/2) =cot i l l (1 - µ 2 cosec 2 i).
- The mathematical formulation presented assumes normal irradiance of the incident light on the sample but this can be altered for acute incidence.
- The incident light being white, the intensity of the component colours scattered in this direction varies as the inverse eighth power of the wave-length, so that the resultant light is a rich blue.