In one embodiment {HEAD ~ a dispersive element} is used to reflect {TAIL ~ the input beam} at different angles depending on the incident wavelength 
is used to reflect
In one embodiment { HEAD ~ a dispersive element } is used to reflect { TAIL ~ the input beam } at different angles depending on the incident wavelength
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH