In a Young's double slit experiment with light of wavelength $\lambda$, the separation of slits is $d$ and distance of screen is $D$ such that $D \gg d \gg \lambda$. If the Fringe width is $\beta$, the distance from point of maximum intensity to the point where intensity falls to half of the maximum intensity on either side is:\\
(1) $\frac { \beta } { 4 }$\\
(2) $\frac { \beta } { 3 }$\\
(3) $\frac { \beta } { 6 }$\\
(4) $\frac { \beta } { 2 }$