Angular spread in diffraction grating

[profbored]

hi,
i have a question here tt i hope some kind souls out there can clarify with me.
if i shine a monochromatic light, let's say 500 nm, at a diffraction grating, will i onli get spectral lines, or will there be some orders which give me an angular spread? cos when u draw the graph of intensity against sin(theta) for a monochromatic diffraction grating, u get a detectable spread for each peak.

 

[Doc Al]

The intensity pattern of a diffraction grating shows a set of bright lines (at the primary maxima) which get brighter and narrower as the number of slits in the grating increase. Of course there is an angular spread, but for all practical purposes the sharp peaks are "lines".

This may help: http://230nsc1.phy-astr.gsu.edu/hbase/phyopt/gratint.html#c1

 

[Graeme Robinson]

When a monochromatic light is shone on a diffraction grating, you will not only get spectral lines, but also an angular spread. This is because a diffraction grating works by diffracting light into different orders, which are determined by the spacing of the grating and the wavelength of the light. Each order corresponds to a different angle of diffraction, resulting in an angular spread of the light. This is why when you plot the intensity against sin(theta) for a monochromatic diffraction grating, you will see a detectable spread for each peak. So, in summary, the diffraction grating not only produces spectral lines, but also an angular spread of the light.