54. We are given the “number of lines per millimeter” (which is a common way to express 1/dfor diffraction gratings); thus, 1d= 160lines/mm ⇒d= 6.25×10−6 m . (a) We solve Eq. 36-25 for θwith various values of mand λ. We show here the m = 2 and λ = 460 nm calculation: ()9111610 m)sinsinsin0.14728.46 .6.25 10 mmdλ−−−−−⎛⎞2(460×====°⎜⎟×⎝⎠Similarly, we get 11.81° for m = 2 and λ = 640 nm, 12.75° for m = 3 and λ = 460 nm, and 17.89° for m = 3 and λ = 640 nm. The first indication of overlap occurs when we compute the angle for m = 4 and λ = 460 nm; the result is 17.12° which clearly shows overlap with the large-wavelength portion of the
This is the end of the preview. Sign up
access the rest of the document.