107. (a) The central diffraction envelope spans the range – θ1< < +1where 11sin,aλ−=which could be further simplified ifthe small-angle approximation were justified (which it is not, since ais so small). The maxima in the double-slit pattern are at mmd=−sin,1λso that our range specification becomes 111sinsinsin,madaλλ−−−⎛⎞⎛ ⎞−<<+⎜⎟⎜ ⎟⎝⎠⎝ ⎠which we change (since sine is a monotonically increasing function in the fourth and first quadrants, where all these angles lie) to
This is the end of the preview. Sign up
access the rest of the document.