S
L—lens透镜
G1—half-silvered mirror半镀银镜
G2—compensation mirror补偿镜
M1,M2 reflecting mirror反射镜
4.Michelson’s Interferometer
The path of a particular ray,
E—eyes and telescope眼和望远镜
M1
M2
G1 G2
L
E
M’1
E
S
M1
M2
G1 G2
L
When M2 has been moved
one –half a wavelength,
optical path difference
is changed by one
wavelength,
Discuss,
2/?
当视场中看到 N个
条纹移过时,M2
平移的距离为,
2
?Nd ?
迈克尔逊干涉仪的应用,
?测量微小长度的变化；
?测量光波长。
历史上迈克尔逊曾用此干
涉仪测定红隔线的波长,
?
A
dC
4696.6438??
150C.1atm的干燥空气中
1927年国际会议规定,
dCm ?13.15531641 ?
rKm ?73.16507631 ?1983年国际 17届计量
会议规定,
sCm 2 9 9 7 9 2 4 5 8/11 ??C为光速
1960年国际会议规定,
Example,Two 20cm glass tubes are placed in the two arms of a
Michelson’s interferometer respectively,One is vacuum and the
other is filled up with Ar gas,Considering the light from extended
source S（ ?=5460A） falls on the interferometer,If Ar gas is
drawn off,a shift of 205 fringes occurs,Find the refractive
index of Ar gas,
E
S
M1
M2
G1 G2
L
?kln ??? )1(2
lkn 2/1 ????
20.02
1046.52 0 5 7
?
??? ?
Solve,
31028.0 ??? 0 0 0 2 8.1?n
l
l