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Svanbro, Angelica
Publications (9 of 9) Show all publications
Hällstig, E. & Svanbro, A. (2007). Characterization and compensation of decorrelations in interferometric set-ups using active optics (ed.). In: (Ed.), Wolfgang Osten; Christophe Gorecki; Erik L. Novak (Ed.), Optical Measurement Systems for Industrial Inspection V: . Paper presented at Optical Measurement Systems for Industrial Inspection : 18/07/2007 - 18/07/2007 (pp. 661619). Bellingham, Wash.: SPIE - International Society for Optical Engineering
Open this publication in new window or tab >>Characterization and compensation of decorrelations in interferometric set-ups using active optics
2007 (English)In: Optical Measurement Systems for Industrial Inspection V / [ed] Wolfgang Osten; Christophe Gorecki; Erik L. Novak, Bellingham, Wash.: SPIE - International Society for Optical Engineering, 2007, p. 661619-Conference paper, Published paper (Refereed)
Abstract [en]

Decorrelation in an interferometric set-up appears due to movements of the speckle pattern. In the case of rigid body movements the effect of decorrelation severely limits the performance of speckle interferometers. If the movement is larger than the speckle size the wanted phase information of the deformation is lost. Phase modulating spatial light modulators (SLMs) provide a new method to non-mechanically deflect and shape light. By using the SLM for scanning the field-of-view and focusing at different distances it is possible to measure intensity speckle patterns in a three-dimensional volume. These intensity images can then be cross correlated to give a three-dimensional correlation coefficient of the speckle pattern. If an SLM is utilized in an interferometric set-up it is possible to compensate for unwanted movements during an experiment. The measured correlation coefficient will then provide information regarding how large movements that are allowed with maintained performance of the interferometer. It is shown that for large movements the SLM can be used to retrieve phase maps.

Place, publisher, year, edition, pages
Bellingham, Wash.: SPIE - International Society for Optical Engineering, 2007
Series
Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X ; 6616
National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-35236 (URN)10.1117/12.726054 (DOI)000251243000039 ()2-s2.0-36248967092 (Scopus ID)9b010410-79a6-11dd-b356-000ea68e967b (Local ID)978-0819467584 (ISBN)9b010410-79a6-11dd-b356-000ea68e967b (Archive number)9b010410-79a6-11dd-b356-000ea68e967b (OAI)
Conference
Optical Measurement Systems for Industrial Inspection : 18/07/2007 - 18/07/2007
Note
Validerad; 2007; 20080903 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-07-10Bibliographically approved
Svanbro, A. & Sjödahl, M. (2006). Complex amplitude correlation for compensation of large in-plane motion in digital speckle pattern interferometry (ed.). Paper presented at . Applied Optics, 45(34), 8641-8647
Open this publication in new window or tab >>Complex amplitude correlation for compensation of large in-plane motion in digital speckle pattern interferometry
2006 (English)In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 45, no 34, p. 8641-8647Article in journal (Refereed) Published
Abstract [en]

The use of complex amplitude correlation to compensate for large in-plane motion in digital speckle pattern interferometry is investigated. The result is compared with experiments where digital speckle photography (DSP) is used for compensation. An advantage of using complex amplitude correlation instead of intensity correlation (as in DSP) is that the phase change describing the deformation is retrieved directly from the correlation peak, and there is no need to compensate for the large movement and then use the interferometric algorithms. A discovered drawback of this method is that the correlation values drop quickly if a phase gradient larger than π is present in the subimages used for cross correlation. This means that, for the complex amplitude correlation to be used, the size of the subimages must be well chosen or a third parämeter in the cross-correlation algorithm that compensates for the phase variation is needed. Correlation values and wrapped phase maps from the two techniques (intensity and complex amplitude correlation) are presented.

National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-14090 (URN)10.1364/AO.45.008641 (DOI)000242473800009 ()2-s2.0-33846486807 (Scopus ID)d688e350-aef8-11dc-8c11-000ea68e967b (Local ID)d688e350-aef8-11dc-8c11-000ea68e967b (Archive number)d688e350-aef8-11dc-8c11-000ea68e967b (OAI)
Note
Validerad; 2006; 20071220 (mike)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Svanbro, A. (2006). DSPI: complex amplitude correlation for large in-plane compensations and phase evaluation (ed.). In: (Ed.), Pierre Slangen; Christine Cerruti (Ed.), Speckle06: speckles, from grains to flowers ; 13 - 15 September 2006, Nimes, France ; [proceedings]. Paper presented at Speckle 06 : 13/09/2006 - 15/09/2006 (pp. 63410I). Bellingham, Wash: SPIE - International Society for Optical Engineering
Open this publication in new window or tab >>DSPI: complex amplitude correlation for large in-plane compensations and phase evaluation
2006 (English)In: Speckle06: speckles, from grains to flowers ; 13 - 15 September 2006, Nimes, France ; [proceedings] / [ed] Pierre Slangen; Christine Cerruti, Bellingham, Wash: SPIE - International Society for Optical Engineering, 2006, p. 63410I-Conference paper, Published paper (Refereed)
Abstract [en]

The use of complex amplitude correlation to determine the deformation field for in-plane motions in digital speckle pattern interferometry (DSPI) is investigated. The result is compared to experiments where only DSPI-algorithms, as well as where combined DSPI - intensity correlation are used. Experiments with and without large rigid body motions are studied. An advantage of using complex amplitude correlation instead of intensity correlation is that the phase change describing the deformation is retrieved directly from the correlation peak and there is no need to compensate for the large movement and then use interferometric algorithms to obtain the phase information. A discovered drawback of this method is that the correlation values drops very quick if there is a phase gradient larger than K across the sub image used for the cross correlation. This means that in order to use the complex amplitude correlation the size of the subimages must be proportional to the magnitude of the present deformation gradient. Or, a third parameter in the crosscorrelation algorithm that compensates for the phase variation is needed.

Place, publisher, year, edition, pages
Bellingham, Wash: SPIE - International Society for Optical Engineering, 2006
Series
Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X ; 6341
National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-33067 (URN)10.1117/12.695285 (DOI)000241191500018 ()2-s2.0-33749857487 (Scopus ID)7d4c21f0-adb9-11de-8293-000ea68e967b (Local ID)9780819464262 (ISBN)7d4c21f0-adb9-11de-8293-000ea68e967b (Archive number)7d4c21f0-adb9-11de-8293-000ea68e967b (OAI)
Conference
Speckle 06 : 13/09/2006 - 15/09/2006
Note

Validerad; 2006; 20090930 (ysko)

Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-07-10Bibliographically approved
Svanbro, A. (2004). In-plane dynamic speckle interferometry: comparison between a combined speckle interferometry/speckle correlation and an update of the reference image (ed.). Paper presented at . Applied Optics, 43(21), 4172-4177
Open this publication in new window or tab >>In-plane dynamic speckle interferometry: comparison between a combined speckle interferometry/speckle correlation and an update of the reference image
2004 (English)In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 43, no 21, p. 4172-4177Article in journal (Refereed) Published
Abstract [en]

A common problem during study of, for instance, tensile tests with interferometers is that the sample moves too much so that the speckles decorrelate and no phase information is obtained. Two ways to overcome this problem are compared: a combination of speckle interferometry and speckle correlation and a method in which the reference image is updated during the experiment. The comparison shows that both techniques can be used to measure the deformation of an object even if it is exposed to rigid body motions. Both techniques are applied to measurements of microscale deformation fields of an adhesive joint in a carbon-fiber epoxy composite

National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-6552 (URN)10.1364/AO.43.004172 (DOI)000222898600008 ()2-s2.0-3442885911 (Scopus ID)4c920270-6f6c-11db-962b-000ea68e967b (Local ID)4c920270-6f6c-11db-962b-000ea68e967b (Archive number)4c920270-6f6c-11db-962b-000ea68e967b (OAI)
Note
Validerad; 2004; 20060926 (cira)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Svanbro, A. (2004). Speckle interferometry and correlation applied to large-displacement fields (ed.). (Doctoral dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Speckle interferometry and correlation applied to large-displacement fields
2004 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

A common problem in experimental mechanics is that when a sample is studied in e.g. a tensile test machine, the sample is often exposed to rigid body motions at the same time as small deformations occur. These two movements, the rigid body motion and the deformation, are often talked about as displacement fields. The sought deformation field is often in the micrometer range while the rigid body motions often are of millimetre or centimetre size. Therefore, it is often a problem to resolve the deformation field since it is drowned by the larger movement of the object. The displacement field can be measured with methods like speckle correlation, but the results might be of too poor accuracy to resolve the deformation field. Interferometric methods on the other hand might measure the deformation field but the rigid body motion makes the fringes disappear. In this thesis two methods are presented that makes it possible to master such measuring situations: a combination of speckle interferometry/speckle correlation and a method where the reference image is updated frequently during the experiment. Both theory and experiments are presented. For the combined speckle interferometry/speckle correlation, it is shown that the information necessary to apply the speckle correlation method is already available in interferometric recordings. With only minor changes in the calculation procedures, the speckle motion in the recordings can be determined. Interference fringes, which have disappeared due to large speckle motions, are retrieved by digital compensation for this motion. The speckle correlation technique gives the motion of the whole surface of the object so different areas of the object can move different amounts and in different directions and it is still possible to retrieve the fringes describing the deformation field. Updating the reference image during the experiment is another method used. As soon as the specimen has moved 1/10 of a speckle the reference image is updated in order to avoid speckle decorrelation. In this way the total movement of the surface is added up during the experiment and a phase map describing the displacement of the object is achieved. Finally, the magnitude of the shear in shearography is measured using speckle correlation. This allows quantitative measurements of the spatial derivative of the deformation field in shearography.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2004. p. 50
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544 ; 2004:05
National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-17299 (URN)2b168890-6f77-11db-962b-000ea68e967b (Local ID)2b168890-6f77-11db-962b-000ea68e967b (Archive number)2b168890-6f77-11db-962b-000ea68e967b (OAI)
Note
Godkänd; 2004; 20061030 (haneit)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Molin, N.-E., Sjödahl, M., Gren, P. & Svanbro, A. (2004). Speckle photography combined with speckle interferometry (ed.). Paper presented at . Optics and lasers in engineering, 41(4), 673-686
Open this publication in new window or tab >>Speckle photography combined with speckle interferometry
2004 (English)In: Optics and lasers in engineering, ISSN 0143-8166, E-ISSN 1873-0302, Vol. 41, no 4, p. 673-686Article in journal (Refereed) Published
Abstract [en]

By combining speckle interferometry (SI) measurements with speckle photography, the fringe visibility can be kept high despite the presence of a large bulk or rotating motion of the object. This combined technique improves the usability and measuring range of both pulsed and phase-stepped Sl-methods. This paper reviews the theory of fringe formation in Sl and shows some recent applications of this combined technique

National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-10173 (URN)10.1016/S0143-8166(02)00175-6 (DOI)000188925000007 ()2-s2.0-0347594746 (Scopus ID)8eecfe20-6f73-11db-962b-000ea68e967b (Local ID)8eecfe20-6f73-11db-962b-000ea68e967b (Archive number)8eecfe20-6f73-11db-962b-000ea68e967b (OAI)
Note
Validerad; 2004; 20060926 (cira)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Svanbro, A., Huntley, J. & Davila, A. (2003). Optimal re-referencing rate for in-plane dynamic speckle interferometry (ed.). Paper presented at . Applied Optics, 42(2), 251-258
Open this publication in new window or tab >>Optimal re-referencing rate for in-plane dynamic speckle interferometry
2003 (English)In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 42, no 2, p. 251-258Article in journal (Refereed) Published
Abstract [en]

We investigate experimentally the optimal rate at which the reference speckle pattern should be updated when dynamic speckle interferometry is used to measure transient in-plane displacement fields. Images are captured with a high-speed camera and phase shifting and phase unwrapping are done temporally. For a wide range of in-plane velocities, up to a maximum of 40% of the Nyquist limit, the random errors in the calculated displacement field are minimized by updating the reference speckle pattern after a speckle displacement of 1 /10 of the pixel spacing. The technique is applied to measurements of microscale deformation fields within an adhesive joint in a carbon-fiber epoxy composite.

National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-10472 (URN)10.1364/AO.42.000251 (DOI)000180232000009 ()2-s2.0-0037428363 (Scopus ID)94a3fa00-6f76-11db-962b-000ea68e967b (Local ID)94a3fa00-6f76-11db-962b-000ea68e967b (Archive number)94a3fa00-6f76-11db-962b-000ea68e967b (OAI)
Note
Validerad; 2003; 20060926 (cira)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Molin, N.-E., Svanbro, A., Gren, P. & Sjödahl, M. (2001). Combined digital speckle photography (DSP) and interferometry (ed.). In: (Ed.), (Ed.), Second international conference on experimental mechanics: . Paper presented at International Conference on Experimental Mechanics : 29/11/2000 - 01/12/2000. Bellingham, Wash: SPIE - International Society for Optical Engineering
Open this publication in new window or tab >>Combined digital speckle photography (DSP) and interferometry
2001 (English)In: Second international conference on experimental mechanics, Bellingham, Wash: SPIE - International Society for Optical Engineering, 2001Conference paper, Published paper (Refereed)
Abstract [en]

A general problem in optical metrology is to measure a deformation field when this field is added to a translation or a rotational motion. Methods like Speckle Photography (SP) do handle large rigid body motions but the results might be of too poor accuracy to resolve the deformation field. Interferometric methods on the other hand might measure the deformation field but the bulk motion makes the fringes disappear. By combining Digital Speckle Photography, Dsp, (also called digital correlation) with Speckle Interferometry, SI, (also called ESPI, DSPI, TV holography, pulsed TV holography) or with shearography (TV shearography) such measuring situations can be mastered.

Place, publisher, year, edition, pages
Bellingham, Wash: SPIE - International Society for Optical Engineering, 2001
Series
Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X ; 4317
National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-32411 (URN)6e827a20-fefc-11db-b19d-000ea68e967b (Local ID)819439983 (ISBN)6e827a20-fefc-11db-b19d-000ea68e967b (Archive number)6e827a20-fefc-11db-b19d-000ea68e967b (OAI)
Conference
International Conference on Experimental Mechanics : 29/11/2000 - 01/12/2000
Note
Godkänd; 2001; 20070510 (cira)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Mohan, N., Svanbro, A., Sjödahl, M. & Molin, N.-E. (2001). Dual-beam symmetric illumination-observation TV holography system for measurements (ed.). Paper presented at . Optical Engineering: The Journal of SPIE, 40(12), 2780-2787
Open this publication in new window or tab >>Dual-beam symmetric illumination-observation TV holography system for measurements
2001 (English)In: Optical Engineering: The Journal of SPIE, ISSN 0091-3286, E-ISSN 1560-2303, Vol. 40, no 12, p. 2780-2787Article in journal (Refereed) Published
Abstract [en]

The Leendertz dual-beam symmetric illumination-normal observation arrangement is widely employed for real time evaluation of in-plane displacement components as well as surface shape. Instead of observing along the optical axis, we have examined the Leendertz arrangement by observing the scattered light along the direction of the illumination beams, and imaged it as two separate images onto the photo sensor of a CCD camera. The interferometer is a combination of two channels, each of which measures independently and simultaneously the information pertaining to either the in-plane displacement component of a deformation vector, or the surface relief variation of a three-dimensional object. In addition, a summary of possible measurements that can be carried out from the present arrangement is also highlighted. Experimental results using a four-frame phase shifting technique are illustrated

National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-11626 (URN)aa51a180-6f68-11db-962b-000ea68e967b (Local ID)aa51a180-6f68-11db-962b-000ea68e967b (Archive number)aa51a180-6f68-11db-962b-000ea68e967b (OAI)
Note
Validerad; 2001; 20060929 (cira)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved

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