Single Slit

• Conditions necessary to observe significant diffraction effects for a wave incident upon an obstacle


  • λ (approx.) = size of obstrictle or
• Intensity


  Power (energy transfered per second) per unit area => (Wm²)
• Diagram to show the diffraction pattern observed when monochromatic light is shone through asingle slit

  1. Central maximum, intense, twice width of outer

  2. (subsidiary) outer fringes
• Interference pattern produced on the screen


  • Bright Fringes
  • very intense central maximum
  • dark
• Effect on the central maximum of increasing the slit width


  decreases diffraction, central maximum narrows and is more intense
• Diffraction central maximum


  • Widens (less Interse)
  • Same power
• Effect on central maximum of increasing incident wavelength


  Increases diffraction, central maximum widens