Speckle phenomenon and its potential for metrology

Transcription

1 Speckle phenomenon and its potential for metrology PART II Petr Šmíd Institute of Physics of the Academy of Sciences of the Czech Republic, Joint Laboratory of Optics of Palacky University and Institute of Physics of the Academy of Sciences of the Czech Republic, 17. listopadu 50a, Olomouc Joint International Physics Summer School Optics, Olomouc (28th August - 1st September 2017)

2 4. Speckle s potential for metrology Lecture's Outline A. Speckle correlation method (laboratory activity), B. Electronic speckle pattern interferometry. Laboratory Object under test 2/13

3 Speckle correlation method 1977 description of speckle field propagation and its use for detection of in-plane object motion, YAMAGUCHI, I. et al. Theory and applications of dynamic laser speckles due to in-plane object motion. Opt. Acta 24(7), pp (1977). Speckle displacement at the sensor plane (x-axis): A X =σ a X where LO cos 2θ S σ= +cos θ O LS cos θ O Prof. I. Yamaguchi (Speckle06, Nimes, 2006). 3/13

4 Speckle correlation method - Principle Object under test illuminated with a laser beam and subject to general deformation results in: speckle pattern displacement, speckle decorrelation (change in the structure of the speckle pattern). Determination of the speckle pattern displacement statistically normalized crosscorrelation function of the speckle patterns. Speckle pattern displacement 4/13

5 Correlation analysis - Principle Step 1 (shift 0): pixel: 1st 2nd 3rd 10th f:... c(0) = f1 g1+f2 g2+f3 g g: Step 2 (shift +1): pixel: 1st 2nd 3rd 10th... f: c(1) = f2 g1+f3 g2+f4 g g: Step 3 (shift +2), Step 4 (shift +3),... c(2) = f3 g1+f4 g2+f5 g3+... c(3) = f4 g1+f5 g2+f6 g /13

6 Correlation analysis Identical signals I1 and I2 Displacement Δxt between signals I1 and I2, partial change in similarity between both signals No similarity between signals I1 and I2 The speckle pattern displacement evaluation of small deformation tensor components (translation, rotation, elastic deformation). description of deformation of an elementary area of object's surface under investigation. 6/13

7 Speckle correlation method Applications Object's static translation free-space (100; 1000) μm, image field (1; 100) μm. Object's normal vibration measuring range (5; 100) Hz, vibration amplitude (10; 1000) μm. Laboratory set-up for object's translation measurement Object's velocity profile measuring range (different for in-plane and out-of-plane translation), measuring range (10 150) µm s-1. Device for contactless scanning of object position stability (Patent registered at Industrial Property Office of the Czech Republic). In-plane velocity profile 7/13

8 ESPI Electronic Speckle Pattern Interferometry 1971 suggestion to interconnect speckle interferometry with electronic detection and processing, presented the basic principle of ESPI, Butters J.N. Speckle pattern interferometry using video techniques. J. Soc. PhotoOpt. Instrum. Eng. 10, pp. 5-9 (1971). Butters J.N., Leendertz J.A. Speckle pattern and holographic techniques in engineering metrology. Opt. laser Technol. 3, pp (1971). Full-field method Alternate names Phase-Shifting Speckle Interferometry, TV Holography. 8/13

9 ESPI - Principle ϕr Reference wave: Object wave (before and after object deformation): 1. ϕ O... speckle phase 2. ϕ O+ Δϕ... speckle phase shifted by object deformation Interferograms evaluation: Interferogram Ii before object deformation = Interferogram If after object deformation Low-frequency interference pattern modulated with high-frequency noise (speckle) 9/13

10 ESPI - Applications experimental mechanics (displacement measurement,...), vibration analysis, nondestructive testing and evaluation, 3-D shape analysis of object's surface from generated contours of equal depth. Head of ESPI sensor Q-300 mounted to a bracket Source: 3D-ESPI System Q-300 TCT [online], 2013 [cit ]. Available from WWW: < Thermal expansion of o Flipchip with perfect bonding (left) and defect bonding (right) 10/13

11 ESPI - Producers Germany Dantec Dynamics, Steinbichler Optotechnik, isi-sys. Netherlands Optonor. USA Measuring head of 3D-ESPI system Q-300 (Dantec Dynamics) (Source: Full-Field Measurement for Advanced Material Testing: Product flyer 3D-ESPI system Q-300. Ulm, Germany : Dantec Dynamics. 2 p) Trilion QualitySystems, Lambda Scientific Systems (scientific instruments for experiment education in physics at colleges and universities). Experimental set-up LEOI-26 using ESPI (Lambda Scientific Systems) Source: Lambda Scientific Systems [online], 2012 [cit ]. LEOI-26B Electronic and Laser Speckle Experimental System. Available from WWW: < 11/13

12 ESPI Applications (System Q-300 Dynamics) by Dantec 3D measurement of object's displacement or object's surface displacement Measurement parameters (source: Dantec Dynamics, system Q-300): resolution: 0,03 1 mm adjustable, measuring range: adjustable to any measuring range by change in measurement steps ( mm), measuring area: up to 200 mm x 300 mm. Results of 3D deformation measurement (by Dantec Dynamics) (Source of the pictures: Laseroptische, berührungslose Verformungsanalyse von Biowerkstoffen mit modernen 3D-ESPI Systemen (Application Note - A-Q-100-Q-300-Biowerkstoffe-003a-DE). Ulm, Germany : Dantec Dynamics. 6 p) 12/13

13 5. Conclusion Thank You for Your attention 13/13