Hypre fine structure/spectrum lines and M/s Adam Hilger of London L.C. 0.0001mm. Comprises of two Semi-Silvered optically worked glass plates in mounts, can be fitted on the base in place of Mirror No.1 and Beam Splitter No. 3. In that case one of the plate is-fixed and the other moved parallel to the fixed one by operating the main knob No. 7 or 8.
OPTIONAL ACCESSORIES
(i) Attachment to convert Fabry-Perot Interferometer into Michelson Interferometer & vice-versa.

(ii) Monochromatic source i.e. Sodium Vapour Lamp. Choke for the lamp and enclosure etc. are required. Laser He Ne 2 mw with Power supply for above