Nội dung text Diffraction.pdf
Welcome to Classes BYJU’S WAVE OPTICS S9: Diffraction What you will learn What you already know ▪ YDSE using microwaves ▪ Optical path difference ▪ Effect of placing a thin transparent film in YDSE ▪ Shift in central maxima ▪ No. of fringes shifted ▪ Fresnel diffraction ▪ Fraunhofer diffraction ▪ Condition for dark fringe ▪ Condition for bright fringe
RECAP L t μ Vacuum L′ t = 0 t ∆x Path difference = μ − 1 L Path difference, ∆x = L ′ − L = μL − L optical path = μL PATH DIFFERENCE BETWEEN TWO PARALLEL WAVES DUE TO A DENSER MEDIUM Covering the distance L in medium of refractive index μ is equivalent to a distance μL in vacuum which we call optical path length.