PH-PS-1
Nanoscale profilometry based on spectrally resolved white-light interferometry
I. Likhachev1, V. Pustovoy2
1General Physics Institute, Laser Physics, Moscow, Russian Federation 2General Physics Institute, Laser Physics Department, Moscow, Russian Federation
Based on the method of Spectrally Resolved White-Light Interferometry (SRWLI), an all optical technique for measuring the surface profiles is proposed. The distinguishing features of the technique are the following:
-the possibility of high-precision absolute distance measurement (not only its variation); no need to calibrate before starting measurements; -a large dynamic range of measurements;
-insensitivity of the measurement result to smooth changes in the spectrum of the radiation source, its drift, and optical power level;
-the possibility of carrying out remote measurements performed by selecting the required length of fiber;
-insensitivity of the measuring probe to electromagnetic interference; -small system size determined by the use of fiber optic components. The XY accuracy of the mechanical stage position is about 1 nm, but in practice the XY accuracy was limited by the light beam width which amounted to about 10 micrometer. The vertical (Z) position of the sample can be controlled with accuracy of 1 nm. All the XYZ coordinates measurements require about 300 ms of time.
References
[1] I. G. Likhachev, V. I. Pustovoy, V. V. Svetikov, and V. I. Krasovskii, Monitoring two-coordinate positioning by means of optical spectral coding, Journ. of Optical Technology, 2018, Vol. 85, Issue 12, pp. 255-258.
[2] I. G. Likhachev, V. I. Pustovoy, V. V. Svetikov, Optical spectral encoding for nanopositioning, The 18th International Conference on Laser Optics ICL0-2018, St. Petersburg, Russia, 4-8 June, 2018.