Optical Scanning Interferometer for Measuring Surface Flatness
Original Publication Date: 1981-Jun-01
Included in the Prior Art Database: 2005-Feb-11
This scanning interferometer is arranged for measuring surface flatness with an error of less than Plus or minus 5 nanometers. The interferometer is sh schematically; the components shown in the smaller rectangle 6 are fixed relative to one another but move as a unit vertically between the components shown in the larger rectangle 8, which moves all of the components horizontally to impart an X-Y scanning motion to the beam from the laser 10. The beam from the stationary laser 10 is reflected upward by a mirror 11 and to the left by a mirror 12. As can be seen, if the mirrors 11 and 12 are moved in the X-scan direction noted in the figure, the beam will move in the X-direction, and if the mirror 12 is moved vertically, the beam will move in the Y-direction.