Gas Refractive Index by Michelson Interferometer

• Michelson interferometer apparatus with is consists of beam splitter, two silver mirror, metallic base and micrometer.
• Red laser diode with holder
• Plan concave lens with holder.
• Air cavity
• Compressor, manual
• Pressure gauge, mechanical
• Gas connectors, rubber
• Gas valve


• In this experiment, we can study the interference by Michelson interferometry which is In a Michelson interferometer, light is split up into two beams by a half-silvered glass plate (amplitude splitting), reflected by two mirrors, and passed again through the glass plate to produce interference phenomena behind it.
• The refractive index of the air is changed due to its pressure, so sealed cavity placed in the laser beam path and measuring the change of air cavity pressure with number of interference fringes.