824.1 Light waves and the coherent condition of waves Ar=n, A=2A(n=0, 1, 2, . constructive Ar=(2n+1), A=0(n=0, 1, 2,)destructive In another words The phase difference 8 pk(巧2一)÷2z Ar=nh, Spath =2nT(n=0, 1, 2, . in phase △r=(2n+1) 2 =(2n+1)(n=0,1,2, O t of of phase s24.1 Light waves and the coherent condition of waves Same frequency and same direction of motion A, cos( at +ou) x2=A2 cos(at+p2) xsr +x Acos(ot+φ) A=A,+A A=y4+A2+24142cos(-q) A1sing+A2sin吗 P=arct A, cos+ A, coso7 , 0 ( 0,1,2, ) 2 (2 1) , 2 ( 0,1,2, ) 1 L L ∆ = + = = ∆ = = = r n A n r n A A n λ λ constructive destructive In another words: = k r − r = ∆r λ π δ 2 ( ) The phase difference path 2 1 , (2 1) ( 0,1,2, ) 2 (2 1) , 2 ( 0,1,2, ) path path L L ∆ = + = + = ∆ = = = r n n n r n n n δ π λ λ δ π out of phase in phase §24.1 Light waves and the coherent condition of waves 2 cos( ) 1 2 2 1 2 2 2 A = A1 + A + A A φ −φ 1 1 2 2 1 1 2 2 cos cos sin sin arctg φ φ φ φ φ A A A A + + = cos( ) 1 2 = ω + φ = + A t x x x A A1 A2 r r r = + A r A1 r A2 r ω ω ω x 1 x 2 x φ φ1 φ 2 x Same frequency and same direction of motion cos( ) 1 = 1 ω + φ 1 x A t cos( ) 2 = 2 ω + ϕ 2 x A t §24.1 Light waves and the coherent condition of waves