3. Young's double-slit Experiment Dark fringe Bright fringe Thomas Young, 1773 1829 English physicist, medical doctor, and Egyptologist Also the inventor of Young‘s Double slit modulus(strength of materials) Single slit Light sour (single wavelength)
Thomas Young, 1773 – 1829 English physicist, medical doctor, and Egyptologist Also the inventor of Young’s modulus (strength of materials) 3. Young’s Double-Slit Experiment
Young's double-slit experiment max m max mIn nax nIn nax First barrier Second barrier nax (b) (a) Viewing screen
Young’s double-slit experiment
d sin e Viewing screen δ= d sin e=m^,m=0,±1,±2, for bright fringes δ=dsne=(m+2)λ,m=0,±1,±2,,, for dark fringes P1143
The positions of the fringes observed in Young’s experiment can easily be computed with the help of the following diagram. = d sin = m, m = 0, 1, 2, . . . for bright fringes = d sin = (m+ ½) , m = 0, 1, 2, . . . for dark fringes P 1143
Bright Dark fringes fringes +2 +2 H=+1 Central bright fringe O 1 =-2