Remote Sensing for Transparent Fluid Pressure by Laser Speckle

Transcription

1 American Journal of Science and Technology 2017; 4(5): ISSN: Remote Sensing for Transparent Fluid Pressure by Laser Speckle Sabah Mohammed Hadi 1, *, Mayada Badry Al-Quzweny 2, Aed Ibrahim Owaid 1 1 Renewable Energy Directorate, Ministry of Science and Technology, Baghdad, Iraq 2 Department of Physics, College of Science, Baghdad University, Baghdad, Iraq address sabah_sabah_777@yahoo.com (S. M. Hadi) * Corresponding author Keywords Fraunhofer Ring, Pressure, Optical, Laser, Remote, Image Received: April 6, 2017 Accepted: September 30, 2017 Published: December 5, 2017 Citation Sabah Mohammed Hadi, Mayada Badry Al-Quzweny, Aed Ibrahim Owaid. Remote Sensing for Transparent Fluid Pressure by Laser Speckle. American Journal of Science and Technology. Vol. 4, No. 5, 2017, pp Abstract In this study optical arrangement was applied to find pressure of air and water with macro impurities using laser speckle, the uses this technique need available and cheap devices. Experimental method was done in the laboratory environment and got results of sense pressure change using laser diffraction (LD). Remote sensing for small change in pressure of impurity fluid was detected by utilize CCD camera connected with personal computer, in this technique the relation of change in pressure with changes in the images which represented by Fraunhofer diffraction ring from circular aperture that appears after image processing by MAT LAB program. 1. Introduction The arrival of the laser in 1960 brought with it a new phenomenon. When laser light illuminates a diffuse surface, the high coherence of the light produces a random interference effect a sort of coherent noise. At first, researchers called the effect granularity, but soon the name speckle became more popular [1]. Laser has effective influences in the development of different techniques to open doors in science and knowledge [2]. One of these techniques was speckle, the speckle phenomenon has long been familiar, but only the introduction of lasers has brought a deeper understanding [3]. In the beginning, laser speckle is often an unwanted effect. Lasers are generally used for their ability to focus and manipulate light, but due to the properties of light and its coherence, interference patterns such as speckle are inevitable. This complex pattern is usually considered background noise and can skew light intensity reading [4]. Speckles are no longer regarded merely as a noise element, but as carrier information to be used in different applications [3]. Over the decades, since the invention of lasers, researchers have discussed the relationship between surface roughness and speckle pattern statistical properties as a new method for off-line as well as on-line surface measurements [5]. Optical non-contact methods can play an important role, because they are contact free and fast. So optical techniques which are based on the speckle imaging technique have been used in last decades due to their advantages [6, 8]. Speckle patterns that produced by scattering laser have been utilized for many important optical sensing of physical properties of inhomogeneous media or surface, deformation has been measured using image processing method [9], Laser speckle contrast analysis is a full-field laser speckle technique for measuring flow velocity. It is the only proposed technique that uses the spatial statistics of laser speckle [10]. Measurement of natural convection heat transfer

2 92 Sabah Mohammed Hadi et al.: Remote Sensing for Transparent Fluid Pressure by Laser Speckle coefficients and measurement of combusting flame temperature profiles [11]. Laser Speckle Contrast Analysis (LASCA) as a tool for analyzing material concentration qualitatively [12] laser speckle contrast imaging is a technique useful for the characterization of scattering particle dynamics with high spatial and temporal resolution. Unfortunately, the image processing is slow. The advantages of laser speckle contrast imaging have created considerable interest in its application to the study of blood perfusion in tissues such as the retina and the cerebral cortices [13]. Not only interference pattern noticed diffraction pattern was appear in our work. In general the diffraction kinds are: a. Fraunhofer diffraction for which the source and the field to be studied are both effectively an infinite distance from the aperture. b. Fresnel diffraction for which the source and the field to be studied are at a large distances from the aperture compared to the wave length but at small enough distances to require consideration of the effect of phase difference between secondary wavelets from different points in the aperture, even when the source and the field to be considered are on a normal to the screen. c. diffraction by apertures of the order of small dimensions to the wave -length. d. diffraction by aperture of order of a wave- length in diameter observed in and near the aperture [14]. The scattering pattern depends on ratio of particle diameter (D) and wave length of incident light (λ) accordingly, the scattering pattern will change not only with change in size of particles but also as result of a change in wave length. Depending on the (D/λ) ratio it can be distinguished among the Fraunhofer, Mie and Rayleigh scattering. The Fraunhofer scattering occurs if particle size is at least 5 to 6 times larger the (λ). The Rayleigh scattering occurs when the particle size is considerably smaller then (λ) (e.g. 10 times) while Mie scattering occurs if the (D/λ) ratio is around one [15]. Fraunhofer diffraction is a common phenomenon in our daily lives, which can be realized by experiment and simulation easily. Nowadays, the Fraunhofer diffraction has been widely applied to measure the diameter of filaments and holes. in addition to width of slit and determination of particle size, especially when the charge-coupled device (CCD) is adopted, the real-time and noninvasive measurement is realized [15, 16]. in our work interference (speckle) is used to remove effect impurities on images after processing and the diffraction of electromagnetic waves by circular apertures has been used and relation of change Fraunhofer diffraction ring with pressure discussed by two step the first is recognize Fraunhofer ring from images taken with change pressure by remove laser speckle, and the second step by measuring changing diameter of diffraction rings and find relation of change diameters of rings with pressure. 2. Experimental Work The optical arrangement of this experiment consist of power supply was used to keep working for a long time with high stability of intensity with current range from 0.6 ampere to 2 ampere and with a voltage range from 1.5 volt to 15 volt. The required laser in our experiment has some special specifications to match our work, one of these specifications high stability output intensity, and with transverse mode TEM 00 to ensure the laser spot consists of one part. Laser source is with output power less than 500 mw and with wavelength 530nm. In our experiments, camera is an important part of the optical system. It works as a detector to measure the distribution of speckles by transferring image data to computer and processed it with MATLAB program in order to get information about these images. the chamber that used in our experiments consist of iron cylinder with open ends, these ends covered with high transparent glass for visible light, and this chamber connected with pressure gauge. The optical arrangement is illustrated in figure 1. Important part of this experiment is measure the effect of noise light in laboratory before starting by take image and take intensity of light to remove it from image before image processing. Figure 1. Optical arrangement of the experiment. When laser cross ends of the chamber through transparent media and if that chamber with cylindrical shape the Airy pattern in the Fraunhofer region of a field appear. The airy pattern that captured by CCD camera with air pressure (1.5 Bar) Fraunhofer ring around the airy disk appear after image processing, the image of transmittance laser and its processing showing in figure 2.

3 American Journal of Science and Technology 2017; 4(5): Figure 2. a) RGB image of green diode laser cross air with pressure 1.5 Bar, and b) Processing of the image. The images of every change in pressure from (0-1.5) Bar to air with impurities and water with impurities are illustrated in the tables (1, 2) below. Table 1. Illustrated change pressure of impurity air with Fraunhofer ring diameter around the airy disk. Pressure (bar) Image process image Diameter (pixel)

4 94 Sabah Mohammed Hadi et al.: Remote Sensing for Transparent Fluid Pressure by Laser Speckle Table 2. Illustrated change pressure of impurity water with Fraunhofer ring diameter around the airy disk. pressure image process image Diameter (pixel) Results and Discussion Remote sensing got great step in technology of produce different devices with developing in imaging systems that is help to measure various physical parameters. One of these physical parameters is the pressure. In this paper pressure of liquids was measured depending on changing diameter of Fraunhofer ring with change pressure of Transparent Fluid (air, water) with macro impurities that appear because of diffraction from circular aperture the ring in these images, diffraction (Fraunhofer ring) and interference pattern (speckle) capturing by CCD camera. The images that capturing processed in MATLAB program to recognize Fraunhofer ring that use as detector of change pressure. Where the change in pressure effect on density of fluid and this have direct effect on diffraction so, the Fraunhofer ring change, this change in pressure change density of impurities too and this effect on speckle image this effect can be sensing after image processing to remove it from image and get good visibility of Fraunhofer ring. this done by built program to recognize edge of the ring the relation of change Fraunhofer ring in pixel unit with change pressure in bar unit explained with linear fitting equations in figure 3.

5 American Journal of Science and Technology 2017; 4(5): Figure 3. a) Show change Fraunhofer ring with air pressure, b) Show change Fraunhofer ring with air pressure. 4. Conclusion Optical method with simple arrangement can be used to measure pressure of transparent impurity fluid (air, water), this method apple us to get good sensing of change pressure, and give potential to remote sensing of pressure that by changing Fraunhofer ring diameter. This method of measurement (optical method) can be used to sense small change in pressure with high accuracy and overlooking impurities density in transparent fluid which effect on capturing image. This effect of impurities can be removed by image processing where the effect of impurities represented by laser speckle. So the visibility of Fraunhofer ring depending on remove laser speckle from image, this operation depends on density of impurities and CCD camera resolution. In addition to computer program that is used in your image processing. Acknowledgements This research was supported by the optics laboratory in science collage so we like to thank Dr. kahtann and all member in the laboratory for help. References [1] J. David Briersʹʹ Laser Speckle Contrast Imaging for Measuring Blood Flowʹʹ OpticaApplicata, Vol. XXXVII, No. 1 2, (2007). [2] M. Hanabusa and A. Namiki, "Appl. Phys. Lett. 35: (1979). [3] H. J. Tizinni, ʹʹPhysical Proberties of Specklesʹʹ, Academic Press. Chapter 2, P. 5 -ISBN (1978). [4] Salvatore Barra, ʹʹ A study of Scattered Coherent Light: Interference of Double Imposed Laser Speckleʹʹ Ph.D. Thesis, University of New York (2000). [5] Rong-Shung Lu, G. Tian, D. Gledhill and S. Ward, ʹʹGrinding Surface Roughness Measurement Based on the Cooccurrence Matrix of Speckle Pattern Textureʹʹ, Appl. Opt. 45: , (2006). [6] MaheshChand, A. Mehta, R. Sharma, V. N. Ojha and K. P. Chaudhary, ʹʹRoughness Measurement Using Optical Profiler with Self Reference Laser and Stylus Instrument A comparative Studyʹʹ, Pure and Appl. phy. 49: , (2011). [7] F. Gascon and F. Salazar, ʹʹSimulation of Rough Surfaces and Analysis of Roughness by MATLABʹʹ, In Tech 564: , (2011). [8] F. Salazar, T. Belengure, J. Garcia and G. Ramos ʹʹOn Roughness Measurement by Angular Speckle Correlationʹʹ, P. A. N. XIX: , (2012). [9] R. Balamurugan and S. Muruganand, "Electronic Laser Speckle Interferometer for Displacement Measurement using Digital Image Processing Technique" Journal of Image and Graphics, Vol 1, No. 1, (2013). [10] J. David Briers and Siaˆn Webster"Laser Speckle Contrast Analysis (LASCA): A Nonscanning, Full-Field Technique for Monitoring Capillary Blood Flow" Journal of Biomedical Optics 1 (2): , (1996). [11] K. D. Kihm"Applications of Laser Speckle Photography for Thermal Flow Problems"Optics and asers in Engineering 29: , (1998). [12] D. Chicea "Biospeckle Size and Contrast Measurement Application in Particle Sizing and Concentration Assessment" Rom. Journal Phys., Vol. 52, Nos. 5 7: , (2007). [13] W. James Tom, AdrienPonticorvo, and Andrew K. Dunn"Efficient Processing of Laser Speckle Contrast Images"IEEE Transactions on Medical Imaging, Vol. 27 No. 12 (2008). [14] C. L. Anderews "Diffraction Pattern of Circular Aperture at Short Distances" Vol. 71 No. 11 (1947).

6 96 Sabah Mohammed Hadi et al.: Remote Sensing for Transparent Fluid Pressure by Laser Speckle [15] ZoranStojanovic, SmiljaMarkovic "Determination of Particle Size Distributions by Laser Diffraction" Technics -New Materials Vol. 21: 11-20, (2012). [16] Yicheng Wu, Jialin Ma, Yi Yang, and Ping Sun " Improvements of Measuring the Width of Fraunhofer Diffraction Fringes Using Fourier Transform" Optik Vol. 126: , (2015).