Light, polarisation unpolarised

Pi Ii/I for linearly polarised incident radiation. In this case, Eq. (1) must be multiplied by the factor (3/8 rr) (1 + pj)/(l + 2pi). (5a). If only the parallel component of scattered radiation is measured the factor is (3/8 tt) (1 + 2 px) . (I = Pi I ). For naturally polarised (unpolarised) or circularly polarised incident light the relevant factors are given in terms of the depolarisation ratio, p , for natural polarisation, where... 

When vertically polarised light is used /, is independent of angle and sin2 qj term vanishes from eq. 8.24. For commonly used unpolarised light is given by... 

With vertically polarised light, is will be independent of angle and sin201 will vanish from Eq. (18), because it has a value of unity. For more commonly used unpolarised light it is readily shown that Eq. (18) reduces to ... 

The expressions for scattered light intensity (and Rayleigh ratio) must be corrected by dividing by the appropriate Cabannes factor. Effectively this is equivalent to replacing the optical constant K as defined in Eq. (24) by Kf and by 2 Kfj for unpolarised and vertically polarised incident light respectively. 

A beam of unpolarised light can be resolved into two linearly polarised components with vibration directions perpendicular to each other. For convenience these can be called the horizontally and vertically polarised components. When the beam enters a transparent medium, each of the two linearly polarised components experiences its own refractive index. 

Unpolarised light of intensity /o can be represented by the sum of two mutually perpendicular plane polarised beams of equal intensity (/o/2). Consequently, by combining the effects shown in Figures 7.4(a) and (b), the light scattered from unpolarised light and observed in the horizontal plane is the sum of contributions from the vertically and horizontally polarised components ... 

Figure 17.2. Light of the same polarisation direction passes through. In contrast to standard Bragg reflectors, chiral multilayers therefore only reflect one-half of the intensity of unpolarised light.

In the case when unpolarised and vertically polarised light are used as the incident beam, K (in eqn (5.29)) becomes Ku and Kv, respectively, and these are given by ... 

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