Scanning simultaneous phase-shifting interferometer
An optical measuring apparatus for comprising, in combination, a polarization type interferometer including a polarization type beam splitter in which a polarized beam of light is split into orthogonally polarized reference and test beams, an array of detectors arranged in a line for creating a plurality of phase shifting interferograms, and a scanning device for moving the object in a direction perpendicular to a long axis of the detectors.
1. An optical measuring apparatus comprising:
a polarization interferometer including a polarization beam splitter in which a polarized beam of light is split into orthogonally polarized reference and test beams;
a non-polarizing beam splitter for splitting the test and reference beams equally into multiple channels;
an array of detectors arranged in a line for creating a plurality of phase shifting interferograms
wherein each of said detectors is covered with a common quarter wave plate and separate linear polarizers, each of said polarizers having different polarization directions, whereby a value of a phase shift between the test and reference beams for each channel can be controlled by adjusting angles of polarization direction; and
a scanning device for moving the object in a direction perpendicular to a long axis of the detectors.
2. The apparatus of claim 1 , wherein the detectors comprise pixilated detectors.
3. The apparatus of claim 1 , wherein the interferometer is a Twyman-Green polarization interferometer.
4. The apparatus of claim 1 , wherein the interferometer is a Fizeau polarization interferometer.
5. The apparatus of claim 2 , wherein the pixilated detectors comprise linear CCD detectors.
6. The apparatus of claim 2 , wherein the pixilated detectors comprise an array of three linear detectors.
7. The measuring apparatus of claim 1 , wherein the moving stage is a linear translation stage.
8. The apparatus of claim 7 , wherein rate of motion of the translation stage is synchronized with a rate of data collection.
9. The apparatus of claim 8 , wherein phase information obtained from said linear detectors are combined together to create a 3D map of the measured surface.
10. The apparatus of claim 8 , wherein phase information is collected by a computer and a 3D map is constructed using the computer.
11. An optical measuring apparatus comprising:
a polarization interferometer including a polarization beam splitter in which a polarized beam of light is split into orthogonally polarized reference and test beams;
a non-polarizing beam splitter for splitting the test and reference beams equally into multiple channels;
an array of detectors arranged in a row for creating a plurality of phase shifting interferograms;
wherein each of said detectors is covered with a common quarter wave plate and separate linear polarizers, each of said polarizers having different polarization directions, whereby a value of a phase shift between the test and reference beams for each channel can be controlled by adjusting angles of polarization direction; and
a scanning device attached to the interferometer for moving the interferometer in a direction perpendicular to a long axis of the detectors.
12. The apparatus of claim 11 , wherein the detectors comprise pixilated detectors.
13. The apparatus of claim 11 , wherein the interferometer is a Twyman-Green polarization interferometer.
14. The apparatus of claim 11 , wherein the interferometer is a Fizeau polarization interferometer.
15. The apparatus of claim 12 , wherein the pixilated detectors comprise linear CCD detectors.
16. The apparatus of claim 12 , wherein the pixilated detectors comprise an array of three linear detectors.
17. The measuring apparatus of claim 11 , wherein the moving stage is a linear translation stage.
18. The apparatus of claim 17 , wherein rate of motion of the translation stage is synchronized with a rate of data collection.
19. The apparatus of claim 18 , wherein phase information obtained from said linear detectors are combined together to create a 3D map of the measured surface.
20. The apparatus of claim 18 , wherein phase information is collected by a computer and a 3D map is constructed using the computer.