Question

range. msm e fram tha heam splitter and obsarva 130 bright spots. You raplace the rad filter with the blue filter and absarva a hright blue spot in the interfaromater. You now move the movable minrar towards tha heam splitter and ohserva 110 bright spots. Datermine displacement (include sign) of the moveable mirror. (Assume the positive direction is away from the beam splitter.) e final How much does the path difference change when the mirror is moved (cither direction) by a half wavelength? See if you can express the distance moved by the mirror when using either light source in terms of the number of bright spats and the wavelength of the light. tyou know the displacement while using each light source, how can you determine the final displacement? pm

You are using a hydrogen discharge tube and high quality red and blue light filters as the light source for a Michelson interferometer. The hydrogen discharge tube provides light of several different wavelengths (colors) in the visible range. The red light in the hydrogen spectrum has a wavelength of 656.3 nm and the blue light has a wavelength of 434.0 nm. When using the discharge tube and the red filter as the light source, you view a bright red spot in the viewing area of the interferometer. You now move the movable mirror away from the beam splitter and observe 130 bright spots. You replace the red filter with the blue filter and observe a bright blue spot in the interferometer. You now move the movable mirror towards the beam splitter and observe 110 bright spots. Determine the final displacement (include sign) of the moveable mirror. (Assume the positive direction is away from the beam splitter.)

Answer 1

path diference Apots Ans. The when observed gou light (A (130) with red bright 2 d2- 2d, osition of spliter when distance 30 - 6 S6. 3nm AY = fram the move a bte mirr or abserved bright Apois afe 3o fixcd miror and between the d the beam plter The path i erence betadeen the fwo wques uhen bvightpots wih 440m you observed lo 24 - 2d, dithe rom thespliter moveable mirror position af the new The displaccment fthe movable mirror Subtracting 0 and SS 2 (d2-4,)d-d,)= 6SA 6sx 656-3X10- 55x434 x (4 18-79 Xio M d2-d2 the final displacement 8-79