Results of the use of self-focusing in Kerr liquids for the measurement of small wave-front distortions transmitted through a transparent optical sample are presented. Using controlled self-focusing to decrease the spot size of the deflected beam, we have been able to improve the measurement resolution by an order of magnitude compared with that achieved with a conventional Hartmann detector. We examine a variety of materials to determine the optimal nonlinear medium and demonstrate measurements of absolute wave-front deviations at the level of λ/3000. A prototype of a new device, the scanning nonlinear Hartmann sensor, is described.
© 2002 Optical Society of America
(120.4640) Instrumentation, measurement, and metrology : Optical instruments
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(120.6650) Instrumentation, measurement, and metrology : Surface measurements, figure
(190.3270) Nonlinear optics : Kerr effect
Anatoly K. Poteomkin, Anatoly N. Mal’shakov, Nikolay F. Andreev, and David H. Reitze, "Use of self-focusing for measurements of ultrasmall (less than λ/3000) wave-front distortions," J. Opt. Soc. Am. B 19, 650-655 (2002)