Full set of Notes with Fill-Ins - San Jose State University

Chem 155 Unit 12 230 of 316For two light rays of identical power P i but differentfrequency the total signal will be:P(δ) = P i cos(2 π δ ν 1 ) + P i cos(2 π δ ν 2 )For identical BP(δ) = P ( cos(2 π δ ν 1 ) + cos(2 π δ ν 2 ) )What is P(δ) when δ = 0?B( cos(0)+cos(0) ) = 2BSo, when will P(δ) be 2B again?In other words, at what next δ value >0 will the twodifferent wavelengths ν 1 and ν 2 both give ‘bright’signals again?δ ν 1 = some integerδ ν 2 = some integer ± 1δ ν 1 = δ ν 1 ± 1δν 1 - δ ν 2 = ±1i.e. they have ‘slipped’ one wavelength and are bothbright again –so, in this case: ν 1 - ν 2 = Δν = 1/δPage 230 of 316