double slit interference

double slit interference

1. to observe interference of light

   • illuminate two closely spaced parallel slits using a suitable light source
     • slits - coherent sources of waves
       • they emit light waves with a constant phase difference and the same frequency
   • fringes formed due to interference of light from the two slits
     • young's fringes
       • alternate bright and dark fringes
         • evenly spaced and parallel to the double slits
     • bright fringe is formed
       • light waves from each slit arrive in phase with each other
     • dark fringe is formed
       • light waves from the two slits arrive 180° out of phase

2. fringe separation equation

   • fringes become widely spaced if
     • distance from the slits to screen is increased
     • wavelength of light is increased
     • slit spacing is reduced
       • (slit spacing is the distance btwn the centres of the slits)

Images and files in the map