Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687391
G. Barbastathis
Imaging the internal structure of quasi-transparent three-dimensional (3D) objects is one of the most challenging tasks for optical systems. If the light propagates coherently through the volumetric object, then collection of phase projections from different angles and tomographic reconstruction are required. However, a single shot from a high space-bandwidth-product camera is often sufficient to yield 3D information if the object is sufficiently sparse. For incoherent 3D sources or scatterers, the mutual intensity of the propagated field has sufficient degrees of freedom to reconstruct the source but it is limited by the sensitivity (contrast) of the interferometric measurement. We describe two complementary methods of phase recovery. (1) For the coherent sparse case, which typically leads to rapid phase oscillations at the exit pupil, we have implemented several generations of digital holographic imaging systems which can be deployed underwater to image, e.g. aquatic organisms, seed particles, or bubbles in a flow. (2) For slowly varying optical density profiles, we have been investigating phase recovery via the Transport of Intensity Equation (TIE) and we have developed methods to improve contrast and eliminate the inherent scanning requirement by exploiting the (known) object dispersion. We will present experimental results and discuss these methods comparatively.
{"title":"Quantitative phase retrieval","authors":"G. Barbastathis","doi":"10.1109/ISOT.2010.5687391","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687391","url":null,"abstract":"Imaging the internal structure of quasi-transparent three-dimensional (3D) objects is one of the most challenging tasks for optical systems. If the light propagates coherently through the volumetric object, then collection of phase projections from different angles and tomographic reconstruction are required. However, a single shot from a high space-bandwidth-product camera is often sufficient to yield 3D information if the object is sufficiently sparse. For incoherent 3D sources or scatterers, the mutual intensity of the propagated field has sufficient degrees of freedom to reconstruct the source but it is limited by the sensitivity (contrast) of the interferometric measurement. We describe two complementary methods of phase recovery. (1) For the coherent sparse case, which typically leads to rapid phase oscillations at the exit pupil, we have implemented several generations of digital holographic imaging systems which can be deployed underwater to image, e.g. aquatic organisms, seed particles, or bubbles in a flow. (2) For slowly varying optical density profiles, we have been investigating phase recovery via the Transport of Intensity Equation (TIE) and we have developed methods to improve contrast and eliminate the inherent scanning requirement by exploiting the (known) object dispersion. We will present experimental results and discuss these methods comparatively.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"9 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81526937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687361
Abdellah Lamallem, L. Valet, D. Coquin
This paper deals with the uses of the Earth Mover's Distance for local evaluation of fusion system. Local evaluation is an interesting way to better characterize the system behavior and consequently to have information on which subpart needs to be adjusted. The definition of the subpart mission and its measurement are two key points in this problematic. This paper shows that the use of the Earth Mover's Distance for measuring the mission achievement is a more complete mathematical tool. The efficiency of the approach is illustrated on an information fusion system devoted to 3D image analysis.
{"title":"A separability index based on earth mover's distance for local evaluation of fusion systems","authors":"Abdellah Lamallem, L. Valet, D. Coquin","doi":"10.1109/ISOT.2010.5687361","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687361","url":null,"abstract":"This paper deals with the uses of the Earth Mover's Distance for local evaluation of fusion system. Local evaluation is an interesting way to better characterize the system behavior and consequently to have information on which subpart needs to be adjusted. The definition of the subpart mission and its measurement are two key points in this problematic. This paper shows that the use of the Earth Mover's Distance for measuring the mission achievement is a more complete mathematical tool. The efficiency of the approach is illustrated on an information fusion system devoted to 3D image analysis.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"45 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80893366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687330
C. Pérez, L. Castillo, Leonardo A. Cament
Illumination compensation has proven to be crucial in face detection and face recognition. Several methods for illumination compensation have been developed and tested on the face recognition task using international available face databases. Among the methods with best results are the Discrete Cosine Transform (DCT), Local Normalization (LN) and Self-Quotient Image (SQI). Most of these methods have been applied with great success in face recognition using a principal component classifier (PCA). In the past few years, Local Matching Gabor (LMG) classifiers have shown great success in face classification relative to other classifiers. In this work we optimize several illumination compensation methods using the LMG face classifier. We use ge netic algorithms as the optimization tool. We test our results on the FERET international face database. Results show that face recognition can be significantly improved by illumination compensation methods. The best results are obtained with the optimized LN method which yields a 31% reduction in the total number of errors in the FERET database.
{"title":"Illumination compensation method for local matching Gabor face classifier","authors":"C. Pérez, L. Castillo, Leonardo A. Cament","doi":"10.1109/ISOT.2010.5687330","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687330","url":null,"abstract":"Illumination compensation has proven to be crucial in face detection and face recognition. Several methods for illumination compensation have been developed and tested on the face recognition task using international available face databases. Among the methods with best results are the Discrete Cosine Transform (DCT), Local Normalization (LN) and Self-Quotient Image (SQI). Most of these methods have been applied with great success in face recognition using a principal component classifier (PCA). In the past few years, Local Matching Gabor (LMG) classifiers have shown great success in face classification relative to other classifiers. In this work we optimize several illumination compensation methods using the LMG face classifier. We use ge netic algorithms as the optimization tool. We test our results on the FERET international face database. Results show that face recognition can be significantly improved by illumination compensation methods. The best results are obtained with the optimized LN method which yields a 31% reduction in the total number of errors in the FERET database.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"54 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90779946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687348
Dong Li, Huijie Zhao, Hongzhi Jiang
Three dimensional (3D) shape-measurement systems combining fringe projection and stereo vision utilize phase for dense stereo matching. However, projection of orthogonal fringe patterns and computation of curved epipolar lines due to lens distortion has made traditional phase-based stereo matching time-consuming. This paper presents a phase-based stereo matching method that takes advantage of epipolar line rectification and transforms bi-stereo geometry into epipolar standard geometry. Using phase-shifting techniques to compute ph ase, stereo matching is simplified by searching for the closest phase along horizontal epipolar lines. Compared with the traditional method, this method shortened the stereo matching time by 20 percent. In 3D reconstruction of a plane with high flatness, the 3D shape measurement accuracy was demonstrated to be 0.0178mm. Thus, this method is suitable for applications that require fast speed and high accuracy.
{"title":"Fast phase-based stereo matching method for 3D shape measurement","authors":"Dong Li, Huijie Zhao, Hongzhi Jiang","doi":"10.1109/ISOT.2010.5687348","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687348","url":null,"abstract":"Three dimensional (3D) shape-measurement systems combining fringe projection and stereo vision utilize phase for dense stereo matching. However, projection of orthogonal fringe patterns and computation of curved epipolar lines due to lens distortion has made traditional phase-based stereo matching time-consuming. This paper presents a phase-based stereo matching method that takes advantage of epipolar line rectification and transforms bi-stereo geometry into epipolar standard geometry. Using phase-shifting techniques to compute ph ase, stereo matching is simplified by searching for the closest phase along horizontal epipolar lines. Compared with the traditional method, this method shortened the stereo matching time by 20 percent. In 3D reconstruction of a plane with high flatness, the 3D shape measurement accuracy was demonstrated to be 0.0178mm. Thus, this method is suitable for applications that require fast speed and high accuracy.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"11 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90051732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687307
Y. Lo, T. Pham
An analytical technique based on the Mueller matrix method and the Stokes parameters is proposed for extracting all effective parameters on the principal axis angle, phase retardance, diattenuation axis angle, diattenuation, optical rotation angle and circular diattenuation value of anisotropic optical materials. The linear birefringence, circular birefringence, linear diattenuation, circular diattenuation properties are decoupled within the analytical model. The result demonstrates the feasibility of analytical model in characterizing all effective parameters of anisotropic optical material. Also, it confirms that the proposed fiber-based polarimeter provides a simple alternative to existing fiber-based probes for parameter measurement in the near field or the remote environment. A low birefringence fiber-based polarimeter based on effective parameters and genetic algorithm without using a fiber polarization controller is first proposed confirmatively. As authors' knowledge, this methodology is introduced in this paper cou ld be the most comprehensive algorithm in extracting all parameters in anisotropic optical materials.
{"title":"Characterization on all effective parameters of anisotropic optical material using Stokes polarimeter — Theory and experiment","authors":"Y. Lo, T. Pham","doi":"10.1109/ISOT.2010.5687307","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687307","url":null,"abstract":"An analytical technique based on the Mueller matrix method and the Stokes parameters is proposed for extracting all effective parameters on the principal axis angle, phase retardance, diattenuation axis angle, diattenuation, optical rotation angle and circular diattenuation value of anisotropic optical materials. The linear birefringence, circular birefringence, linear diattenuation, circular diattenuation properties are decoupled within the analytical model. The result demonstrates the feasibility of analytical model in characterizing all effective parameters of anisotropic optical material. Also, it confirms that the proposed fiber-based polarimeter provides a simple alternative to existing fiber-based probes for parameter measurement in the near field or the remote environment. A low birefringence fiber-based polarimeter based on effective parameters and genetic algorithm without using a fiber polarization controller is first proposed confirmatively. As authors' knowledge, this methodology is introduced in this paper cou ld be the most comprehensive algorithm in extracting all parameters in anisotropic optical materials.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"160 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86408221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687378
Yuuto Okuda, Koji Yamashita, I. Fujieda
Spectral imaging of a color document is realized by a modified flat-bed scanner in which its linear image sensor is replaced by a diffraction grating and a two-dimensional image sensor. This illuminant-independent color recording may be ad vantageous for desk-top applications.
{"title":"Spectral imaging with a modified document scanner","authors":"Yuuto Okuda, Koji Yamashita, I. Fujieda","doi":"10.1109/ISOT.2010.5687378","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687378","url":null,"abstract":"Spectral imaging of a color document is realized by a modified flat-bed scanner in which its linear image sensor is replaced by a diffraction grating and a two-dimensional image sensor. This illuminant-independent color recording may be ad vantageous for desk-top applications.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"5 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88602552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687368
A. Rostami, S. Makouei, F. Janabi-Sharifi
In this paper, we design a zero-dispersion shifted fiber based on triangular core graded index single mode optical fiber and consider the transmission parameters fluctuations owing to environmental conditions variations such as temperature. The Transfer Matrix Method (TMM) developed in the cylindrical coordinate [1] is used to obtain the field distribution and guided modes. Meanwhile, design process consists of limited coordinate descent optimization method. In order to estimate the thermal coefficients, the model introduced in [2] is applied. It is found out that the propagation characteristics of the proposed graded index fiber have greater endurance against temperature fluctuations compared to the reported structures based on the multi-clad step index ones.
{"title":"Design and temperature analysis of ZDSF based on triangular graded-index single-mode optical fiber","authors":"A. Rostami, S. Makouei, F. Janabi-Sharifi","doi":"10.1109/ISOT.2010.5687368","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687368","url":null,"abstract":"In this paper, we design a zero-dispersion shifted fiber based on triangular core graded index single mode optical fiber and consider the transmission parameters fluctuations owing to environmental conditions variations such as temperature. The Transfer Matrix Method (TMM) developed in the cylindrical coordinate [1] is used to obtain the field distribution and guided modes. Meanwhile, design process consists of limited coordinate descent optimization method. In order to estimate the thermal coefficients, the model introduced in [2] is applied. It is found out that the propagation characteristics of the proposed graded index fiber have greater endurance against temperature fluctuations compared to the reported structures based on the multi-clad step index ones.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"21 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85603713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687370
A. Rostami, A. Ghanbari, H. Soofi, F. Janabi-Sharifi
In this paper a new strategy to design large mode area photonic crystal fibers with relatively small hole pitches is presented and employed to design fibers with effective mode areas larger than 70µm2 at λ=1.55µm with hole pitch Λ=2.5µm. The idea is based on insertion of circular defect holes in the core area of an HF7 fiber. It is shown that by precisely adjusting the locations and the diameters of these defect holes, field distribution alters in a way that leads to a larger effective mode area than HF7 fiber itself. The validation of the proposed design is carried out by adopting an efficient full-vectorial finite difference frequency domain method with perfectly matched layers for accurate characterization of photonic crystal fibers. Dispersion characteristics of the designed fibers is also investigated and it is shown that the defect insertion has strong dispersion flattening and lowering attitude that can significantly ease the fiber design task for optical communication transmission systems.
{"title":"Enlarging effective mode area of photonic crystal fibers using defected core structures","authors":"A. Rostami, A. Ghanbari, H. Soofi, F. Janabi-Sharifi","doi":"10.1109/ISOT.2010.5687370","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687370","url":null,"abstract":"In this paper a new strategy to design large mode area photonic crystal fibers with relatively small hole pitches is presented and employed to design fibers with effective mode areas larger than 70µm2 at λ=1.55µm with hole pitch Λ=2.5µm. The idea is based on insertion of circular defect holes in the core area of an HF7 fiber. It is shown that by precisely adjusting the locations and the diameters of these defect holes, field distribution alters in a way that leads to a larger effective mode area than HF7 fiber itself. The validation of the proposed design is carried out by adopting an efficient full-vectorial finite difference frequency domain method with perfectly matched layers for accurate characterization of photonic crystal fibers. Dispersion characteristics of the designed fibers is also investigated and it is shown that the defect insertion has strong dispersion flattening and lowering attitude that can significantly ease the fiber design task for optical communication transmission systems.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"37 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74836152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687314
Y. H. Huang, S. Hung, Y. Chen, L. Liu, S. Ng
Phase measurement is a key step in quantitative optical metrology. While phase shifting technique is widely applied for accurate and reliable static or semi-static phase measurement, Fourier and wavelet transforms are often employed for high speed dynamic phase measurement. In our previous papers, the authors had proposed an alternative clustering method for dynamic phase measurement. The proposed method utilizes the phase clustering effect and the prior knowledge of the speckle field to extract the deformed phase map from one single deformed speckle pattern. The clustering method, however, may fail at area with abundant noise and large phase gradient. In this paper, we improve the clustering method by incorporating an advanced phase filtering methods for wrapped phase filtering. The reconstructed wrapped phase map is with very good quality and ready for phase unwrapping with any simple unwrapping algorithms. The basic ideas and the implementation approach will be described in details. Several examples based on shearography and holographic interferometry will be presented. Comparisons between the proposed method and phase shifting method will be made. The results demonstrate the accuracy and robustness of the integrated dynamic phase extraction method. The integrated phase retrieval method proposed here has great potential to simplify optical setup for dynamic phase measurement.
{"title":"Dynamic phase measurement by clustering method","authors":"Y. H. Huang, S. Hung, Y. Chen, L. Liu, S. Ng","doi":"10.1109/ISOT.2010.5687314","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687314","url":null,"abstract":"Phase measurement is a key step in quantitative optical metrology. While phase shifting technique is widely applied for accurate and reliable static or semi-static phase measurement, Fourier and wavelet transforms are often employed for high speed dynamic phase measurement. In our previous papers, the authors had proposed an alternative clustering method for dynamic phase measurement. The proposed method utilizes the phase clustering effect and the prior knowledge of the speckle field to extract the deformed phase map from one single deformed speckle pattern. The clustering method, however, may fail at area with abundant noise and large phase gradient. In this paper, we improve the clustering method by incorporating an advanced phase filtering methods for wrapped phase filtering. The reconstructed wrapped phase map is with very good quality and ready for phase unwrapping with any simple unwrapping algorithms. The basic ideas and the implementation approach will be described in details. Several examples based on shearography and holographic interferometry will be presented. Comparisons between the proposed method and phase shifting method will be made. The results demonstrate the accuracy and robustness of the integrated dynamic phase extraction method. The integrated phase retrieval method proposed here has great potential to simplify optical setup for dynamic phase measurement.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"35 2 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82794227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687365
A. Rostami, H. Rasooli, A. Ghanbari, S. Zabihi, F. Janabi-Sharifi
The electronic conductance at zero temperature through a quantum wire with side-attached asymmetric quantum dot-molecules (as a scatter system) is theoretically studied using the non-interacting Anderson tunneling Hamiltonian method. We show that the asymmetric configuration of QD-scatter system strongly impresses the amplitude and spectrum of quantum wire nanostructure transmission characteristics. It is shown that whenever the balanced number of chains-quantum dots in one molecule is substituted by unbalanced scheme, the number of forbidden mini-bands in quantum wire conductance increases to the sum of the number of quantum dots in two chains and thus the QW-nanostructure electronic conductance contains rich spectral properties due to appearance of the new anti-resonance and resonance points in spectrum. Considering the suitable inner gap between QD-chains in one molecule or outer gap between QD-molecules, can strengthen the amplitude of new resonant peaks in QW conductance spectrum. The proposed asymmetric-QD scatter system idea in this paper opens a new insight on designing quantum wire nanostructures for given electronic conductance.
{"title":"Quantum-wire conductance manipulating by asymmetric quantum dot-molecules","authors":"A. Rostami, H. Rasooli, A. Ghanbari, S. Zabihi, F. Janabi-Sharifi","doi":"10.1109/ISOT.2010.5687365","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687365","url":null,"abstract":"The electronic conductance at zero temperature through a quantum wire with side-attached asymmetric quantum dot-molecules (as a scatter system) is theoretically studied using the non-interacting Anderson tunneling Hamiltonian method. We show that the asymmetric configuration of QD-scatter system strongly impresses the amplitude and spectrum of quantum wire nanostructure transmission characteristics. It is shown that whenever the balanced number of chains-quantum dots in one molecule is substituted by unbalanced scheme, the number of forbidden mini-bands in quantum wire conductance increases to the sum of the number of quantum dots in two chains and thus the QW-nanostructure electronic conductance contains rich spectral properties due to appearance of the new anti-resonance and resonance points in spectrum. Considering the suitable inner gap between QD-chains in one molecule or outer gap between QD-molecules, can strengthen the amplitude of new resonant peaks in QW conductance spectrum. The proposed asymmetric-QD scatter system idea in this paper opens a new insight on designing quantum wire nanostructures for given electronic conductance.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"231 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82751483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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