According to my knowledge, the position of the dark fringes is given by asin(x)=m*lamda (sorry, I do not know how to type equations in here) tan(x)=d/L a=slit width x=angle of diffraction(?) m=no. of order d=distance from the central fringe L=distance between slit and screen By using is equation, I found out that the distance between successive dark fringes is increasing as the order increase. Which means that the width of the bright fringes increase with the order. But, from this webpage (last section), http://dev.physicslab.org/Document....me=PhysicalOptics_InterferenceDiffraction.xml Quote: "In a diffraction pattern, the central maximum has the greatest brightness, with each successive bright fringe getting narrower and dimmer." Which says the opposite. Tried searching the web and this forum but couldn't find any info. Please advice. Thank you.