Question:
Estimate the distance for which ray optics is good approximationv for an aperture of 4 mm and wavelength 400 nm.
Answer:
Fresnel’s distance (ZF) is the distance for which the ray optics is a good approximation. It is given by the relation,
ZF = α2/λ
Where, Aperture width, α = 4 mm = 4 x 10-3 m
Wavelength of light (λ) = 400 nm =400 x 10-9 m
ZF = 4 x 10-3/ 400 x 10-9 = 40 m
Therefore, the distance for which the ray optics is a good approximation is 40 m.
Not what you are looking for? Go ahead and submit the question, we will get back to you.
