2011 06 02 (uned) emadrid mlcalvo ucm m learning y holografia tecnicas compatibles

1. m-Learning and Holography: Compatible techniques? María L. Calvo Departamento de Óptica, Facultad de Ciencias Físicas, Universidad Complutense de Madrid (UCM) II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

2. Outline Introduction: What is m-Learning? Objectives. What is a hologram? In-line Gabor hologram The concept of diffraction: Fresnel zones Classroom accessibility: some results Other proposals. References. II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

3. Introduction: m-Learning Image sensors consists of devices that capture an image for purposes of display or storage. Cell phones are nowadays ubiquitous. Camera phones comprised over 80% of all shipped image sensors in 2008, with recent growth coming from the continuing penetration of dual-camera phones in the global market. Improvement of the technical design provides in 2011 cell phones with resolution of the order of 8 Mpixels (digital camera resolution). These facts provide unique tools for teaching and technological tools. II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

4. [Source: Wikipedia]

5. Objectives Experimental methods for studying the basis of optical phenomena are needed to be extended to class room as a routine tool for students in physics and engineers. These methods can be simplified and easily implemented by the use of the new technical assistance provided by camera phones: classroom accessibility. In 2009, Z. Ben Lakhdar et al. introduced a procedure for studying diffraction and interference by the use of overhead projectors and camera phone image capture. All tools accessible in the class room by the students. This technique can be extended to other optical phenomena, such as Holography. Some discussions arise after the analysis of the experimental results. II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

7. C.V.Raman and N.S.N.Nath obtained evidence of thin grating behavior of an acoustic wave irradiated with light and studied the nature of the diffracted field in 1935.

8. During 20th century an important amount of work was done to introduce new techniques such as digital holography (A. Lohman, J. W. Goodman).

9. The 21st century is called to be the century of information photonics in which holographic techniques appear to be among the most appealing ones.C. V. Raman in his laboratory ca. 1930. II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

10. What is a hologram? Real image A hologram is an interferogram in which it is encoded the amplitude and phase associated to the light wave diffracted by an object (object wave). The encoded information can be retrieved by the light wave diffracted by the hologram (reading the hologram). Virtual image II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

11. In-line holography: Gabor hologram Real image plane II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

12. Example: digital in-line holographic microscopy Holograms generated with a green LED Reconstructed holographic images Images obtained with a Nikon Eclipse TE300 inverted microscope Set-up for a lensless digital holographic microscope with LED illumination. From: L. Repetto, E. Piano, and C. Pontiggia,Lensless digital holographic microscope with light-emitting diode illumination, Opt. Letters, Vol. 29, No. 10, 1132 (May 15, 2004) II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

13. Somehistoryondiffractionexperiments In 1665 Francesco M. Grimaldi (an Italian Jesuit, Bolonia, 1618-1663), developed a simple experiment with a light source (a candle), a slit and a screen. source He was one of the earliest physicists to suggest that light was wavelike in nature. He formulated a geometrical basis for a wave theory of light in his work: “Physicomathesis de lumine, coloribus, et iride, aliisqueannexis” (Bolonia, 1665). He coined the term diffraction. Grimaldi’s experiment was disseminated by HonoreFabri (1607-1688). His publications (1669) allowed Isaac Newton to know on these antecedents. Slit Screen

14. Scheme for the diffraction of a laser beam by a circular aperture xm aperture Laser cavity Detection plane XY (Screen) R Camera phone Fresneldiffractionplane: FresnelZone II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

15. Fresnelzones: definition Area of Fresnel zone number-n: Generally, it is assumed that all areas of the regions are similar ones. II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

16. Fresnel lens hologram From: S. S. Sarkar, P. K. Sahoo, H. H. Solak, C. David, J. F. van derVeen, Fresnel zone plates made by holography in the extreme ultraviolet region, Journal of Physics: Conference Series, 186 012071 (2009).

17. SomeResults:Operating in theclassroom II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

19. Students carry the camera phones.

20. We need a metric tape.

21. We need two types of laser pointers. To compare data: One emitting in green light another emitting in red light.

22. Pictures are taken at fixed distances from the screen.Laser pointers have to be handled with caution. Radiation can be hazardous to eyes. Output power: From 1 to 400 mW/cm2. II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

23. Propagationdistance: 1 m. Red laser pointer (l= 632 nm) Image as captured by the camera phone. Type: P3450 (CMOS camera) Line profile Intensity: 256 gray levels(8 bits) 1pixel: 29 mm. pixels pixels II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

24. Propagationdistance: 1m. Green laser pointer (l = 532 nm.) Image as capturedbythe camera phone. Line profile pixelspixels II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

25. Propagationdistance 3 m. Red laser pointer (l = 632 nm) Image as captured by the camera. Line profile pixels pixels II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

26. Propagationdistance: 3m. Green laser pointer (l = 532 nm.) Image as captured by the camera phone Line profile pixels pixels II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

27. 1 m. propagation diffraction regimes FFT Intensity FFT Phase FFT Intensity FFT Phase II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

28. 3 m. propagation diffraction regimes FFT Intensity FFT Phase FFT Intensity FFT Phase II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

29. Results with another camera phone model Model: Nokia 8600 Luna Resolution: 1200x1600 400 pixels/cm. Original captured images:1200x1600 After image treatment for line profile obtention: 150x150 pixels. Pixel: 25 mm II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

30. Green laser pointerpropagation distance: 242 cm Image as captured by the camera phone Image treated with falsh color for line profile II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

31. Digital image treatment Image converted into grey scale and treated with colormap Phase Square modulus of the FFT: focus II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

32. Other proposals: lab-on-a-chip Holographic optofluidic microscopy Fundamentals: Objects of interest are placed directly on the image sensor (i.e. within less than a few micrometers), and utilize either carefully fabricated sub-micron apertures , or multi-frame processing to improve resolution beyond the sensor pixel size limitation. From: W. Bishara, H. Zhu, and A. Ozcan, Holographic opto-fluidicmicroscopy, Opt Express. 2010 December 20; 18(26): 27499–27510. II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

34. Wide-field-of-view: 23 mm2.

35. Weight: 95 g.

36. Digital sensor array (CMOS).W. Bishara, U. Sikora, O. Mudanyali, T. Su, O. Yaglidere, S. Luckhart and A. Ozcan, Holographic pixel super-resolution in portable lenslesson-chip microscopyusing a fiber-opticarray, Lab Chip, 2011, 11, 1276-1279. II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

37. Conclusions Camera phones are very useful for education and technical purposes. Over the last years, cell phones have become increasingly popular and are ubiquitous. Cell phones are now equipped with text messaging, internet, camera features, and other facilities. Cell phones offer many benefits. Technologues can easily use them as a technical tool. The combination of laser sources and cell phones provides a unique tool for the experimental demonstration of diffraction phenomena in the class room. The great advantage is that it requires a very reduced infrastructure and can be implemented as a micro-device. Combination with digital holographic techniques provides a quite promising tool for imaging data manipulation. II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

38. OtherReferences J. C. Wyatt, FresnelDiffraction.nb (Internet available). Z. Ben Lakhdar, Z.Dhaouadi, H.Ghalila, S.Lahmar and Y. Majdi, “Using mobile camera for a better exploitation and understanding of interference and diffraction experiments”, Proc. The Education and Training in Optics and Photonics (ETOP) (Ed. A. Shore), Proc. SPIE (2009). “Image sensor market set forcyclicgrowth”, NaturePhotonics, vol.3, November 2009. II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

39. GICO-UCM The Interdisciplinary Group for Optical Computing(GICO-UCM): María Luisa Calvo Padilla PavelCheben, National Institute for Microstructural Science, NRC, Ottawa, Canada Tatiana Alieva ÓscarMartínez-Matos José A. Rodrigo (Instituto de Óptica, CSIC) María de la Paz Hernández-Garay Alejandro Cámara Iglesias AitorVillafranca Velasco Acknowledgements: - M. C. Fernández-Panadero (UC3M). - David ParedesBarato (under graduate student, Statistical Optics, 2010, UCM). http://www.ucm.es/info/giboucm II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011

40. Example: some recent applications: the Gabor superlens (a) From: K. Stollberg, A. Brückner, J. Duparré, P. Dannberg, A. Bräuer and A. Tünnermann, “The Gabor superlens as an alternative wafer-level camera approach inspired by superposition compound eyes of nocturnal insects”, Opt. Express, Vol. 17, No. 18, 15747 (31 August 2009 ). II Jornadas eMadrid sobre e-Learning, UNED, 1-2 junio 2011