In: Physics
Take the diffraction grating slide outside in the evening. Look through the grating at streetlights, car lights, or neon lights.
Describe how the spectrum of each light differs from that of the laser.
Shine the white light of a flashlight or desk lamp through the diffraction grating onto a nearby wall in a partially darkened room.
Describe how the spectrum of each light differs from that of the laser.
Lasers are highly monochromatic light source so when a diffraction grating is used, it will give out an interference pattern enveloped in a diffraction pattern in which all the fringes are of the same color (same wavelength).
On the other hand, if the same grating is used to analyze car lights, neon lights or streetlights, you will find that they give out doublets or triplets for every fringe in the interference pattern and this is because these lights are not highly monochromatic and contains a two or three wavelengths.
If white light is used, the resultant interference pattern will contain interference pattern for all the colors in the visible spectrum (VIBGYOR). This is because, every wavelength gets dispersed proportionately in accordance to its wavelength.