2.牛顿环 T R 光程差 a B 6=2nd+ M R2=r2+(R-d)2=r2+R2-2Rd+d AB ≈r2+R2-2Ral 2R 明纹2n 2k-k=12.3 2R 暗纹 2 2R+=(2k+1)x,k=0,12,2. 牛顿环 d C • A B R r O 2 2   = nd + 光程差 r R Rd R r R d r R Rd d 2 ( ) 2 2 2 2 2 2 2 2 2  + − = + − = + − + R r d 2 2 = 明纹 , 1,2,3, 2 2 2 2 2 2 + = k k = R r n   暗纹 , 0,1,2, 2 (2 1) 2 2 2 2 + = k + k = R r n   • S L A M B T