講義案例成果22-2diffraction by a circular aperture

1、一 Diffraction by a circular aperture Central fringeThe diameter of first minimum d二 Raleighs criterion (瑞利判據(jù))For two incoherent point source, the central maximum of the diffraction pattern of one source is centered on the first minimum of the diffraction pattern of the other, then the two source can

2、 be seen distinct with this apparatus. jfPPath differenceCentral fringefirst order minimumQ三 ResolvabilityWhen the image of S1 and S2 just be seen distinctly*y0*For the image of S1y1For the image of S2minimum angular resolutionResolving power of optical element The four stars are just distinguishabl

3、e with the telescope Then they cant be seen distinctly if the telescopes diameter is smaller. Solution:(a)(b)SP. 3(p.900) A circular converging lens, with diameter d=32 mm and focal length f=24cm, forms images of distance point objects in the focal plane of the lens. Light of wavelength =550nm is us

4、ed. (a) Considering diffraction by the lens, what angular separation must two distant point objects have to satisfy Rayleighs criterion? (b) What is the separation x of the center of the images in the focal plane? Two bright points on blackboard are 2mm apart. They are viewed by the eye at a distanc

5、e L. The entrance opening (pupil) of the viewers eye has a diameter of 3.0mm. If the eye were perfect, the limiting factor for resolution of the two point would be diffraction. In that limit, how large could we make L and still have the points seen as separate entities?Solution:Exp. LEyeseagle human

6、Diameter of pupil Angle of mini-mum resolutiondistance of mini-mum resolutionL=3mEyes2.562.710-41.110-40.81mm0.33mmThe Hubble space telesc-ope is a reflecting teles-cope that was placed in orbit above the Earths atmosphere. Its objective diameter is 2.4 m. For visible light, say l=550 nm, q=2.810-7 rad.D=350m阿雷西博是一個射電望遠(yuǎn)鏡，它是世界上最 大的單臺射電望遠(yuǎn)鏡，直徑350米，設(shè)在中美洲波多黎各（美國 托管地） 利用貴州省南部熔巖洼地建造500米孔徑球面射電望遠(yuǎn)鏡，面積則相當(dāng)于25個足球場那么大，預(yù)算