Article,
Low Cost Device to Measure the Thickness of Thin Transparent Films
International Journal on Communication, 2 (1): 4 (March 2011)
Abstract
There is often a requirement to fabricate thin glass
plates for prototyping purposes in a research lab. For example
to make a prototype of an optic filter there is a need to fabricate
a number of thin glass plates and in most moderately equipped
optic research laboratory there is facility to etch these glass
plates, but lacks instruments to measure its thickness. Our main
purpose is to design a system which is cost friendly and is
capable of measuring the thickness with a resolution lesser than
1μm.A combination of Michelson interferometer and an
electronic fringe counter makes up this instrument. The
interferometer produces the fringes which can be made to shift
in relation to the thickness of the film to be measured. The
number of fringes shifted is recorded be the counter using which
the thickness can be determined (note: the refractive index of
the plate should be known)
