DISPERSION OF POLYCHROMATIC LIGHT WITH A PRISM Polychromatic Ray Infrared Red Orange Yellow Green Blue Violet Ultraviolet monochromatic Ray SLIT PRISM Polychromatic Ray Monochromatic Ray Prism - spray out the spectrum and choose the certain wavelength (l) that you want by slit.DISPERSION OF POLYCHROMATIC LIGHT WITH A PRISM Polychromatic Ray Infrared Red Orange Yellow Green Blue Violet Ultraviolet monochromatic Ray SLIT PRISM Polychromatic Ray Monochromatic Ray Prism - spray out the spectrum and choose the certain wavelength (l) that you want by slit