Chapter 30The Wave Nature of LightInterference
Chapter 30 The Wave Nature of Light; Interference
Huygens'principleNature of light: particles or wave?Huygens' principle:Points on wave front → sources of tiny waveletsNew wave front -→ envelope of all the wavelets(tangent to all of them)New wave front& traveling direction2
Huygens’ principle 2 Nature of light: particles or wave? Huygens’ principle: Points on wave front → sources of tiny wavelets New wave front → envelope of all the wavelets (tangent to all of them) New wave front & traveling direction
Wave Nature of LightDiffraction:Refraction:Index of refractionn=c / v
Wave Nature of Light Diffraction: Refraction: Index of refraction: n c v = /
Interferenceconditions1) Same frequency (monochromatic)2) Same oscillation direction (polarization)3)Constant phase difference6260595057504350760049003800Monochromatic: a very narrow range of 2
Interference conditions 1) Same frequency (monochromatic) 2) Same oscillation direction (polarization) 3) Constant phase difference Monochromatic: a very narrow range of λ
CoherenceLight sources produce “wave trains"’ of light(random phaseSrelation)independentA great many of such wave trains → incoherentConstant phase relation → coherent1) laser2) separate from one source
Coherence Light sources produce “wave trains” of light · · (random phase relation) independent A great many of such wave trains → incoherent Constant phase relation → coherent 1) laser 2) separate from one source