P5f Nature of Waves

P5f Nature of Waves

1. Coherent waves

   • Laser light is monochromatic, all the waves have the same wavelength and frequency. It may also be coherent, and this is needed to produce the stable interference patterns.
   • Coherent wave sources produce light which means that each wave has one frequency or wavelength. Each wave also has the same amplitude and are in phase with one another .
   • The crests and troughs occur in the same places for waves that have the same phases, they do not coincide when waves are out of phase.

2. Interference

   • Constructive interference - when two waves from the same source arrive in phase
   • Destructive interfereance - when two waves from the same source arrive half a wavelength out of phase.