Optical head based on the focus error signal and a calibration system to measure vibration and displacement

ANDRÉS D. AGUILAR, ENEAS N. MOREL, JORGE R. TORGA

Rio de Janeiro

Congreso; 23 ABCM International Congress of Mechanical Engineering; 2015

Associação Brasileira de Ciências Mecânicas

In this work we present a study of an optical system based on the focus error signal technique to measure vibrations and surface displacement as a function of time. The device used was an optical head that focuses a laser beam onto the surface of interest and measure the position of the sample as a function of time by means of the focus error signal produced by the reflected beam. Sample reflectivity and alignment are issues that condition its application range, different solutions are proposed. Experimental configurations including two different calibration systems are presented. The main characteristics that make such a device desirable for a range of applications in non-contact measurements are discussed and experimental results are presented.