Pub Date : 2012-05-21DOI: 10.1109/SOPO.2012.6271121
Jiasheng Tian, Qiaoyun Liu, P. Tan, Jian-Hui Shi, M. Fan, Deng Yue, Y. Pei
In this paper some key technologies of an optical cavity for a compact Terahertz(THz) Source Based on Free Electron Lasers(FEL) were studied. Firstly, the theory of THz radiation was analyzed by some calculations. The high quality electronic bunch beams with energy 5.6-9.9MeV can produce THz radiation with frequency 1-10THz. Secondly, the configuration of the optical cavity was calculated and studied, and some conditions were discussed in order to obtain a single resonance mode. Thirdly, The loss caused by the diffraction and the coupling aperture was calculated. Finally, an idea of designing an optical cavity and some important data were given.
{"title":"The Study of the Optical Cavity for a Compact Terahertz Source Based on Free Electron Lasers","authors":"Jiasheng Tian, Qiaoyun Liu, P. Tan, Jian-Hui Shi, M. Fan, Deng Yue, Y. Pei","doi":"10.1109/SOPO.2012.6271121","DOIUrl":"https://doi.org/10.1109/SOPO.2012.6271121","url":null,"abstract":"In this paper some key technologies of an optical cavity for a compact Terahertz(THz) Source Based on Free Electron Lasers(FEL) were studied. Firstly, the theory of THz radiation was analyzed by some calculations. The high quality electronic bunch beams with energy 5.6-9.9MeV can produce THz radiation with frequency 1-10THz. Secondly, the configuration of the optical cavity was calculated and studied, and some conditions were discussed in order to obtain a single resonance mode. Thirdly, The loss caused by the diffraction and the coupling aperture was calculated. Finally, an idea of designing an optical cavity and some important data were given.","PeriodicalId":159850,"journal":{"name":"2012 Symposium on Photonics and Optoelectronics","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123572082","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 : 2012-05-21DOI: 10.1109/SOPO.2012.6270553
Shuxia Guo
Oxygen vacancies are frequently invoked to explain the experimental phenomena observed in ZnO, such as the visible emission, photoconduction, and magnetism. The levels induced by oxygen vacancies play a crucial role in reasonable interpretation on experimental data. Optical transition levels related to oxygen vacancies in ZnO have been reported in several recent papers. For the level positions relative to the band edges, there exists difference between different groups due to various methods adopted, even between the results from the same group. Original data related to oxygen vacancies in ZnO in the literatures are reviewed here. We found that the center of photoluminescence caused by VO depends on the initial states of EM, and 2.6 eV is minimum excitation energy (hνexc) for the PL centered at 530 nm. The following conclusions are drawn. Oxygen vacancies are neutral states, and the transition energy ε (0/+) lies in the lower half of the band gap. The first ionization energy is 3.03 eV.
{"title":"Optical Transition Levels Related to Oxygen Vacancies in ZnO","authors":"Shuxia Guo","doi":"10.1109/SOPO.2012.6270553","DOIUrl":"https://doi.org/10.1109/SOPO.2012.6270553","url":null,"abstract":"Oxygen vacancies are frequently invoked to explain the experimental phenomena observed in ZnO, such as the visible emission, photoconduction, and magnetism. The levels induced by oxygen vacancies play a crucial role in reasonable interpretation on experimental data. Optical transition levels related to oxygen vacancies in ZnO have been reported in several recent papers. For the level positions relative to the band edges, there exists difference between different groups due to various methods adopted, even between the results from the same group. Original data related to oxygen vacancies in ZnO in the literatures are reviewed here. We found that the center of photoluminescence caused by VO depends on the initial states of EM, and 2.6 eV is minimum excitation energy (hνexc) for the PL centered at 530 nm. The following conclusions are drawn. Oxygen vacancies are neutral states, and the transition energy ε (0/+) lies in the lower half of the band gap. The first ionization energy is 3.03 eV.","PeriodicalId":159850,"journal":{"name":"2012 Symposium on Photonics and Optoelectronics","volume":"28 11‐12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113956830","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 : 2012-05-21DOI: 10.1109/SOPO.2012.6271005
Z. Mierczyk, M. Zygmunt, T. Drozd, A. Gawlikowski, A. Gietka, M. Jakubaszek, M. Kaszczuk, P. Knysak, A. Młodzianko, M. Muzal, R. Ostrowski, W. Piotrowski, J. Wojtanowski
This article presents the reflectance profilometer, which was designed and constructed in Institute of Optoelectronics of Military University of Technology. The reflectance profilometer is an optoelectronic device based on the laser remote sensing technique. The profilometer fundamental function is to define a shape of terrain along with an identification and analysis of elements of its coverage, characterized by high spatial resolution. The basis of its operating principles is to analyze the reflectance signals for laser radiation from the spectral range of 850-1550nm. The received information is visualized in 3D format, which allows for more accurate, precise and comprehensive way of presentation of the analyzed area model. The developed head is designed for use on unmanned aerial vehicles (UAV).
{"title":"Multispectral Laser Head for Identification and Analysis of Terrain Intended for Use on Unmanned Aerial Vehicle","authors":"Z. Mierczyk, M. Zygmunt, T. Drozd, A. Gawlikowski, A. Gietka, M. Jakubaszek, M. Kaszczuk, P. Knysak, A. Młodzianko, M. Muzal, R. Ostrowski, W. Piotrowski, J. Wojtanowski","doi":"10.1109/SOPO.2012.6271005","DOIUrl":"https://doi.org/10.1109/SOPO.2012.6271005","url":null,"abstract":"This article presents the reflectance profilometer, which was designed and constructed in Institute of Optoelectronics of Military University of Technology. The reflectance profilometer is an optoelectronic device based on the laser remote sensing technique. The profilometer fundamental function is to define a shape of terrain along with an identification and analysis of elements of its coverage, characterized by high spatial resolution. The basis of its operating principles is to analyze the reflectance signals for laser radiation from the spectral range of 850-1550nm. The received information is visualized in 3D format, which allows for more accurate, precise and comprehensive way of presentation of the analyzed area model. The developed head is designed for use on unmanned aerial vehicles (UAV).","PeriodicalId":159850,"journal":{"name":"2012 Symposium on Photonics and Optoelectronics","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126289376","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 : 2012-05-21DOI: 10.1109/SOPO.2012.6270928
Qianghua Li, Shecheng Gao
We completely study the wavelength dependency of polarization dependent loss (PDL) for uniform fiber Bragg gratings (FBGs) written in single mode fibers (SMF). Effective PDL (PDLeff) and simulations are carried out using the coupled mode theory and the Jones formalism. We analyze the evolution with wavelength of PDLeff as a function of the grating parameters and the birefringence value. We demonstrate that the PDLeff evolutions with wavelength can be strongly enhanced by a modification of the grating parameters. Our work brings a complete characterization of PDLeff in FBGs and presents a good agreement between theory and experience.
{"title":"Spectral Characterization of Polarization Dependent Loss in Uniform Fiber Bragg Gratings in Reflection","authors":"Qianghua Li, Shecheng Gao","doi":"10.1109/SOPO.2012.6270928","DOIUrl":"https://doi.org/10.1109/SOPO.2012.6270928","url":null,"abstract":"We completely study the wavelength dependency of polarization dependent loss (PDL) for uniform fiber Bragg gratings (FBGs) written in single mode fibers (SMF). Effective PDL (PDLeff) and simulations are carried out using the coupled mode theory and the Jones formalism. We analyze the evolution with wavelength of PDLeff as a function of the grating parameters and the birefringence value. We demonstrate that the PDLeff evolutions with wavelength can be strongly enhanced by a modification of the grating parameters. Our work brings a complete characterization of PDLeff in FBGs and presents a good agreement between theory and experience.","PeriodicalId":159850,"journal":{"name":"2012 Symposium on Photonics and Optoelectronics","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129787283","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 : 2012-05-21DOI: 10.1109/SOPO.2012.6270523
L. Li, G. Liu, K. Huang, Y. Chen, L. Gong, F. Tang
A channel drop filter combination of a circular ring resonator and two point defect micro-cavities was proposed. The ring resonator works as an energy coupler via capturing the electromagnetic energy propagated in the input waveguide and sends it to the output waveguide at its resonant frequencies. And the point defect micro-cavities are used to further filter the original lightwave. In our designed CDF, the drop efficiency close to 100% at the center normalized frequency 0.342 and nearly 98% at the center normalized frequency 0.334 have been achieved.
{"title":"A New Photonic Crystal Channel Drop Filter","authors":"L. Li, G. Liu, K. Huang, Y. Chen, L. Gong, F. Tang","doi":"10.1109/SOPO.2012.6270523","DOIUrl":"https://doi.org/10.1109/SOPO.2012.6270523","url":null,"abstract":"A channel drop filter combination of a circular ring resonator and two point defect micro-cavities was proposed. The ring resonator works as an energy coupler via capturing the electromagnetic energy propagated in the input waveguide and sends it to the output waveguide at its resonant frequencies. And the point defect micro-cavities are used to further filter the original lightwave. In our designed CDF, the drop efficiency close to 100% at the center normalized frequency 0.342 and nearly 98% at the center normalized frequency 0.334 have been achieved.","PeriodicalId":159850,"journal":{"name":"2012 Symposium on Photonics and Optoelectronics","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129253531","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 : 2012-05-21DOI: 10.1109/SOPO.2012.6270950
Cheng Yang, Rong Lu, Niannian Chen
How to extract the features quickly and correctly is the essential precondition for image identification and classification. As there existing large computation problems in the traditional feature extraction algorithms, this paper proposes a faster algorithm. Firstly, the image connected region is encoded by using the Vertex Chain Code to map as a closed area. Then a unified computational framework is developed to combine the Vertex Chain Code and Discrete Green, turning surface integral into line integral. Experimental results show that this algorithm is fast and effective, and can be used for special area.
{"title":"A Fast Algorithm for Image Geometric Feature Parameters Extraction","authors":"Cheng Yang, Rong Lu, Niannian Chen","doi":"10.1109/SOPO.2012.6270950","DOIUrl":"https://doi.org/10.1109/SOPO.2012.6270950","url":null,"abstract":"How to extract the features quickly and correctly is the essential precondition for image identification and classification. As there existing large computation problems in the traditional feature extraction algorithms, this paper proposes a faster algorithm. Firstly, the image connected region is encoded by using the Vertex Chain Code to map as a closed area. Then a unified computational framework is developed to combine the Vertex Chain Code and Discrete Green, turning surface integral into line integral. Experimental results show that this algorithm is fast and effective, and can be used for special area.","PeriodicalId":159850,"journal":{"name":"2012 Symposium on Photonics and Optoelectronics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129634332","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 : 2012-05-21DOI: 10.1109/SOPO.2012.6270549
Qiu Yang, Yana Zhang, Cheng Yang, Wei Li
Information entropy is often applied as one of masking effect in digital watermarking system. At present, some scholars have used entropy masking to improve the performance of their watermarking algorithm. This paper mainly introduces the entropy masking model in three different domains, and gives experiment report about utilizing spatial domain, DCT domain, and DWT domain entropy masking model in the similar watermarking system. In addition, we analyze the advantages and disadvantages of these models from the aspects of imperceptibility and robustness through our simulation experiment.
{"title":"Information Entropy Used in Digital Watermarking","authors":"Qiu Yang, Yana Zhang, Cheng Yang, Wei Li","doi":"10.1109/SOPO.2012.6270549","DOIUrl":"https://doi.org/10.1109/SOPO.2012.6270549","url":null,"abstract":"Information entropy is often applied as one of masking effect in digital watermarking system. At present, some scholars have used entropy masking to improve the performance of their watermarking algorithm. This paper mainly introduces the entropy masking model in three different domains, and gives experiment report about utilizing spatial domain, DCT domain, and DWT domain entropy masking model in the similar watermarking system. In addition, we analyze the advantages and disadvantages of these models from the aspects of imperceptibility and robustness through our simulation experiment.","PeriodicalId":159850,"journal":{"name":"2012 Symposium on Photonics and Optoelectronics","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128282391","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 : 2012-05-21DOI: 10.1109/SOPO.2012.6271063
M. Leopardi
A physical model is used to describe one or more field-size phenomena and, in representing them, it generates other quantities, which are the final output of the system. Sometimes the required thorough measurement of such quantities can lead to lose the total perception of the phenomenon under investigation. Digital image processing can not and should not obviously replace the measurements, but it can be a useful tool for capturing the global behaviour of the model-system and consequently of reality. This process can be especially effective in cases where, for certain configurations or for simplifying the model to its essential characteristics, the aim is to seek a simple representation, although not completely corresponding to reality.
{"title":"Simulation and Modelling with Digital Image Processing: Hydraulic Models","authors":"M. Leopardi","doi":"10.1109/SOPO.2012.6271063","DOIUrl":"https://doi.org/10.1109/SOPO.2012.6271063","url":null,"abstract":"A physical model is used to describe one or more field-size phenomena and, in representing them, it generates other quantities, which are the final output of the system. Sometimes the required thorough measurement of such quantities can lead to lose the total perception of the phenomenon under investigation. Digital image processing can not and should not obviously replace the measurements, but it can be a useful tool for capturing the global behaviour of the model-system and consequently of reality. This process can be especially effective in cases where, for certain configurations or for simplifying the model to its essential characteristics, the aim is to seek a simple representation, although not completely corresponding to reality.","PeriodicalId":159850,"journal":{"name":"2012 Symposium on Photonics and Optoelectronics","volume":"636 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124976736","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 : 2012-05-21DOI: 10.1109/SOPO.2012.6270918
Xuejun Wang
Thirty nanosecond 1.064 μm laser pulses separated by 150 nanoseconds have been shown up to ten times material removal rates while minimizing redeposition and heat-affected zones. The diameter of hole entrance is approximately 450 μm and half hole taper angle is 12 degree. The internal wall of the hole is bright black, no recast layer, no microcrack, smooth and no burr. The laser bursts drilling model is put forward and instantaneous process of laser drilling is discussed.
{"title":"Ablation Mechanisms of Double Nanosecond Pulses Laser Drilling","authors":"Xuejun Wang","doi":"10.1109/SOPO.2012.6270918","DOIUrl":"https://doi.org/10.1109/SOPO.2012.6270918","url":null,"abstract":"Thirty nanosecond 1.064 μm laser pulses separated by 150 nanoseconds have been shown up to ten times material removal rates while minimizing redeposition and heat-affected zones. The diameter of hole entrance is approximately 450 μm and half hole taper angle is 12 degree. The internal wall of the hole is bright black, no recast layer, no microcrack, smooth and no burr. The laser bursts drilling model is put forward and instantaneous process of laser drilling is discussed.","PeriodicalId":159850,"journal":{"name":"2012 Symposium on Photonics and Optoelectronics","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124986578","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 : 2012-05-21DOI: 10.1109/SOPO.2012.6270998
Hanlei Dong, Fan Wang
The median filter is a common filter, which can get a good result with impulse noise, but it can't work well with Gauss noise. At the meanwhile wavelet transform can remove Gauss noise efficiently. In this paper combined with Biorthogonal wavelet transform and median filtering, an efficient image-denoising method was presented. Experiment result shows that the noise of the image is removed effectively. At the same time, the detail of the image is kept well. The method has better denoising effect than single wavelet thresholding method or median filtering method.
{"title":"Image-Denoising Based on Bior Wavelet Transform and Median Filter","authors":"Hanlei Dong, Fan Wang","doi":"10.1109/SOPO.2012.6270998","DOIUrl":"https://doi.org/10.1109/SOPO.2012.6270998","url":null,"abstract":"The median filter is a common filter, which can get a good result with impulse noise, but it can't work well with Gauss noise. At the meanwhile wavelet transform can remove Gauss noise efficiently. In this paper combined with Biorthogonal wavelet transform and median filtering, an efficient image-denoising method was presented. Experiment result shows that the noise of the image is removed effectively. At the same time, the detail of the image is kept well. The method has better denoising effect than single wavelet thresholding method or median filtering method.","PeriodicalId":159850,"journal":{"name":"2012 Symposium on Photonics and Optoelectronics","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120961896","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：