Dear Vijay

Our group recently bought such an interferometer from "Polytec".

The address in the US is

Polytec Optronics, inc.
3001 Redhill Avenue, Building 5, Suite 102
Costa Mesa,
Ca 92626
Tel. (714) 850-1835
Fax. (714) 850-1831

So far it's working well on our microstructures.

George Cooper