PHYSICS LAB MANUALS

Fabry-Perot Interferometer

TABLES FOR RECORDING DATA

Table 1: Finding the spacing between the etalon

D

(cm)

Order of the fringe

Main scale reading
(cm)

Vernier scale reading
(.01 mm)

Net reading
(cm)

n2

=Rm+n2-Rm2


(cm2)

d

=nD2n2


(cm)





















































































Table 2: Determining the demagnification factor

S.no

No. of fringes expanded (or contracted)

Main scale reading
(cm)

Vernier scale reading
(.01 mm)

Net reading
(cm)

Mirror movement(2)(cm)









































































Table 3: Determining of Wavelength of Light

S.no

No. of fringes expanded (or contracted)

Main scale reading
(cm)

Vernier scale reading
(.01 mm)

Net reading
(cm)

Mirror movement(2)(cm)









































































Plot the following Graphs:
  1. Micrometer movement (cm) vs number of fringes expanded (or contracted) – for both Table 2 and Table 3.
The demagnification factor is related to the slope of the straight line.