DOUBLE-BEAM INTERFEROMETER Russian patent published in 2003 - IPC

FIELD: interferometric measurements. SUBSTANCE: the double- beam interferometer includes a luminescence system, supporting and object branches, integrating lens with a filtering diaphragm in its rear focal plane, and a recording device; the luminescence system has a source of monochromatic radiation and a collimator, the supporting and object branches include two relief-phase gratings installed in the direction of the radiation beam, an optical compensator is installed in the supporting branch. Use is also made of four plane mirrors, one of which is installed directly before the first grating, one - in the supporting branch and one in the object branch between the gratings, and the fourth one - past the second grating, both gratings are made as reflection ones with the same spatial frequency, the gratings are positioned with the working surfaces opposite each other, the slits of both gratings are perpendicular to the plane of the interferometer, and at least one of the gratings is installed for smooth turning round the axis perpendicular to its working surface and passing through its middle, as well as for longitudinal motion along its axis. EFFECT: enhanced precision of interferometric measurements at large dimensions of the working field, expanded spectrum of the interferometer, simplified tuning of the interferometer, reduced cost. 2 dwg