※ 引述《melvyn (Aeneas)》之铭言： : [领域] 光学 : [来源] 课本习题(Pedrotti, Introduction to optics 3rd Ed. : Pearson Education, 2007) : [题目]Q1. The separatopm pf a certain doublet 0.0055 nm at a wavelength of : 490 nm. A variable-spaced Fabry-Perot interferometer is used to : examine the doublet. At what spacing does the (m)th order of one : component coincide with the (m+1)th order of the other. : The ans of Q1 is 2.18 cm : Q2. White light is passed through a Fabry-Perot interferometer in the : arrangement shown in Figure,where the detector is a spectroscope. : A series of bright bands appear.When mercury light is simultaneously : admitted intto the spectroscope slit,150 of the bright bands are : seen to fall between the violet and green lines of mercury at : 435.8 nm and 546.1 nm,respectively.What is the thickness of the : etalon? : Figure:http://0rz.tw/b04d4 : The ans of Q2 is 0.161 mm : [瓶颈] : 这两题我都利用 d = mλ/2 ,可是都与课本给的答案不符 : 想请问错再哪？ L = mλ/2 => λ = 2L/m => dλ/dm = -2L/(m^2) => Δλ≒ (2L/(m^2))*Δm or 将 m = 2L/λ代入可得 => Δλ= ((λ^2)/2L)*Δm => 2L = ((λ^2)/Δλ)*Δm For Q1: Δλ= 0.0055nm ， λ= 490nm 且 Δm = 1 => Ans: 2.18 cm For Q2: Δλ= 546.1nm-435.8nm = 110.3nm ， Δm = 150 且 λ≒ (546.1nm+435.8nm)/2 = 490.95nm => Ans: 0.164 mm (误差有点大) 我想大概是这样吧 有错请指教 --

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