A beam of light has a small wavelength spread δ λ about a central wavelength λ . The beam travels in vacuum until it enters a glass plate at an angle θ relative to the normal to the plate, as shown in

Question

A beam of light has a small wavelength spread $δ λ$ about a central wavelength $λ$ . The beam travels in vacuum until it enters a glass plate at an angle $θ$ relative to the normal to the plate, as shown in figure. The index of refraction of the glass is given by $n (λ)$ . The angular spread $δ θ^{'}$ of the refracted beam is given by

TestHub · Accepted Answer

Snell's law: sin θ = n sin θ ′ ( θ fixed) Differentiate: 0 = sin θ ′ d n + n cos θ ′ d θ ′ d θ ′ = − n tan θ ′ ​ d n δ θ ′ = ​ n tan θ ′ ​ d λ d n ​ δ λ ​

Physics - Geometrical Optics Question with Solution | TestHub

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