The new technique known as “The femtosecond frequency comb technology” has dramatic impact on the diverse fields of precision measurement and nonlinear optical physics. In order to acquire high-precision and high-stability femtosecond comb, it’s necessary to stabilize the repetition rate fRep and the offset frequency f0. This article presents the details of stabilizing and controlling the comb parameter fRep and finally phase lock the repetition rate of femtosecond laser to a radio frequency reference, derived from an atomic clock. In practice, the narrower the bandwidth of lock system (close-loop system), the higher stability we can achieve, but it becomes easier to be unlocked for external disturb. We adopt a method in servo unit to avoid this problem in this paper. The control parameters P and I can be adjusted and optimized more flexibly. The lock steps depend on the special servo system make it easier to find the right parameters and the lock becomes more convenient and quickly. With this idea, the locked time of repetition rate can be as long as the mode-locking time of the laser. The stability of laser can be evaluated by allan deviation. In this research, the contrast of stability of fRep between the locked laser and the unlocked is given. The new lock system is proved reasonable.
{"title":"Study on the repetition rate locking system of the femtosecond laser","authors":"Chunbo Zhao, Tengfei Wu, Li Zhang, Zhenyu Zhu","doi":"10.1117/12.2179217","DOIUrl":"https://doi.org/10.1117/12.2179217","url":null,"abstract":"The new technique known as “The femtosecond frequency comb technology” has dramatic impact on the diverse fields of precision measurement and nonlinear optical physics. In order to acquire high-precision and high-stability femtosecond comb, it’s necessary to stabilize the repetition rate fRep and the offset frequency f0. This article presents the details of stabilizing and controlling the comb parameter fRep and finally phase lock the repetition rate of femtosecond laser to a radio frequency reference, derived from an atomic clock. In practice, the narrower the bandwidth of lock system (close-loop system), the higher stability we can achieve, but it becomes easier to be unlocked for external disturb. We adopt a method in servo unit to avoid this problem in this paper. The control parameters P and I can be adjusted and optimized more flexibly. The lock steps depend on the special servo system make it easier to find the right parameters and the lock becomes more convenient and quickly. With this idea, the locked time of repetition rate can be as long as the mode-locking time of the laser. The stability of laser can be evaluated by allan deviation. In this research, the contrast of stability of fRep between the locked laser and the unlocked is given. The new lock system is proved reasonable.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"358 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131362957","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}
Composite material connected by glue has gained popularity as a replacement for conventional materials and structures to reduce weight and improve strength in the aerospace industry, with the development of material science and structural mechanics. However, the adhesive bonding process is more susceptible to quality variations during manufacturing than traditional joining methods. The integrality, strength and rigidity of product would be broken by disbonding. Infrared thermography is one of several non-destructive testing techniques which can be used for defect detection in aircraft materials. Pulsed infrared thermography has been widely used in aerospace and mechanical manufacture industry because it can offer noncontact, quickly and visual examinations of disbonding defects. However the parameter choosing method is difficult to decide. Investigate the choosing technical parameters for pulse thermograpghy is more important to ensure the product quality and testing efficiency. In this paper, two kinds of defects which are of various size, shape and location below the test surface are planted in the honeycomb structure, they are all tested by pulsed thermography. This paper presents a study of single factor experimental research on damage sample in simulation was carried out. The impact of the power of light source, detection distance, and the wave band of thermography camera on detecting effect is studied. The select principle of technique is made, the principle supplied basis for selection of detecting parameters in real part testing.
{"title":"Investigation on choosing technical parameters for pulse thermography","authors":"Huijuan Li","doi":"10.1117/12.2178781","DOIUrl":"https://doi.org/10.1117/12.2178781","url":null,"abstract":"Composite material connected by glue has gained popularity as a replacement for conventional materials and structures to reduce weight and improve strength in the aerospace industry, with the development of material science and structural mechanics. However, the adhesive bonding process is more susceptible to quality variations during manufacturing than traditional joining methods. The integrality, strength and rigidity of product would be broken by disbonding. Infrared thermography is one of several non-destructive testing techniques which can be used for defect detection in aircraft materials. Pulsed infrared thermography has been widely used in aerospace and mechanical manufacture industry because it can offer noncontact, quickly and visual examinations of disbonding defects. However the parameter choosing method is difficult to decide. Investigate the choosing technical parameters for pulse thermograpghy is more important to ensure the product quality and testing efficiency. In this paper, two kinds of defects which are of various size, shape and location below the test surface are planted in the honeycomb structure, they are all tested by pulsed thermography. This paper presents a study of single factor experimental research on damage sample in simulation was carried out. The impact of the power of light source, detection distance, and the wave band of thermography camera on detecting effect is studied. The select principle of technique is made, the principle supplied basis for selection of detecting parameters in real part testing.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132466367","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}
H. Qiao, Reng Wang, Cuiling Jiao, Wei Gong, Xiang-yang Li
Optically immersed HgCdTe photovoltaic detectors in the 2.5 to 3.2 μm wavelength region operating at near room temperatures have been developed based on HgCdTe graded structure materials grown by opened tube isothermal vapor phase epitaxy (ISOVPE) method on lattice matched CdZnTe substrate. Fourier transformation infrared spectroscopy (FTIR) measurement combined with continuous step wet etching was applied to adjust the cutoff wavelength. The devices were designed and fabricated by traditional n-on-p planar junction process. Optical immersion of micro-lenses by CdZnTe substrate was used to improve the performance of the devices and the hyper-hemispherical micro-lens with a diameter of 1.5mm was made by single point diamond turning method. The optical response area was tested by laser beam induced current (LBIC) scanning measurement, and the result showed that the devices with hyper-hemispherical immersion micro-lens could get a 1mm×1mm response area as designed. The current-voltage characteristic of the devices were measured, and all the devices showed a little increase in the values of zero biased resistance, which was due to a decreased background radiation acceptance angle caused by a hyper-hemispherical structure. The photo response signal and dark noise were also measured before and after the micro-lens fabrication. The signal showed an increase by 20-30 times due to the enlarged photo response area, and the dark noise showed a little decrease which was also due to a limited background radiation acceptance angle. As a result, a multiple factor of four in detectivity enhancement could be achieved by the adoption of hyper-hemispherical immersion micro-lens structures.
{"title":"Development of optically immersed, near-room-temperature HgCdTe photovoltaic detectors","authors":"H. Qiao, Reng Wang, Cuiling Jiao, Wei Gong, Xiang-yang Li","doi":"10.1117/12.2180099","DOIUrl":"https://doi.org/10.1117/12.2180099","url":null,"abstract":"Optically immersed HgCdTe photovoltaic detectors in the 2.5 to 3.2 μm wavelength region operating at near room temperatures have been developed based on HgCdTe graded structure materials grown by opened tube isothermal vapor phase epitaxy (ISOVPE) method on lattice matched CdZnTe substrate. Fourier transformation infrared spectroscopy (FTIR) measurement combined with continuous step wet etching was applied to adjust the cutoff wavelength. The devices were designed and fabricated by traditional n-on-p planar junction process. Optical immersion of micro-lenses by CdZnTe substrate was used to improve the performance of the devices and the hyper-hemispherical micro-lens with a diameter of 1.5mm was made by single point diamond turning method. The optical response area was tested by laser beam induced current (LBIC) scanning measurement, and the result showed that the devices with hyper-hemispherical immersion micro-lens could get a 1mm×1mm response area as designed. The current-voltage characteristic of the devices were measured, and all the devices showed a little increase in the values of zero biased resistance, which was due to a decreased background radiation acceptance angle caused by a hyper-hemispherical structure. The photo response signal and dark noise were also measured before and after the micro-lens fabrication. The signal showed an increase by 20-30 times due to the enlarged photo response area, and the dark noise showed a little decrease which was also due to a limited background radiation acceptance angle. As a result, a multiple factor of four in detectivity enhancement could be achieved by the adoption of hyper-hemispherical immersion micro-lens structures.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"255 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114363372","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}
Terahertz (THz) holography is a frontier technology in terahertz imaging field. However, reconstructed images of holograms are inherently affected by speckle noise, on account of the coherent nature of light scattering. Stationary wavelet transform (SWT) is an effective tool in speckle noise removal. In this paper, two algorithms for despeckling SAR images are implemented to THz images based on SWT, which are threshold estimation and smoothing operation respectively. Denoised images are then quantitatively assessed by speckle index. Experimental results show that the stationary wavelet transform has superior denoising performance and image detail preservation to discrete wavelet transform. In terms of the threshold estimation, high levels of decomposing are needed for better denoising result. The smoothing operation combined with stationary wavelet transform manifests the optimal denoising effect at single decomposition level, with 5×5 average filtering.
{"title":"Terahertz digital holography image denoising using stationary wavelet transform","authors":"Shan-shan Cui, Qi Li, Guang-hao Chen","doi":"10.1117/12.2182877","DOIUrl":"https://doi.org/10.1117/12.2182877","url":null,"abstract":"Terahertz (THz) holography is a frontier technology in terahertz imaging field. However, reconstructed images of holograms are inherently affected by speckle noise, on account of the coherent nature of light scattering. Stationary wavelet transform (SWT) is an effective tool in speckle noise removal. In this paper, two algorithms for despeckling SAR images are implemented to THz images based on SWT, which are threshold estimation and smoothing operation respectively. Denoised images are then quantitatively assessed by speckle index. Experimental results show that the stationary wavelet transform has superior denoising performance and image detail preservation to discrete wavelet transform. In terms of the threshold estimation, high levels of decomposing are needed for better denoising result. The smoothing operation combined with stationary wavelet transform manifests the optimal denoising effect at single decomposition level, with 5×5 average filtering.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116336290","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}
Changqing Cao, Xiaodong Zeng, Xiang Wang, Zhi Lai, L. Luo
Based on the beam characteristics of semiconductor lasers, a new parameter for evaluating beam quality of semiconductor lasers is introduced. The shortcomings of M2 factor used in evaluating beam quality of semiconductor lasers are discussed and its limitations are pointed out. Moreover, some important aspects of the beam quality factor are discussed. The main factors to influence collimating the beam of semiconductor lasers are analyzed. Our results give us grounds to make the following conclusions: the new propagation parameter succeeds in its universality and adaptability.
{"title":"Discussion of beam quality of semiconductor lasers","authors":"Changqing Cao, Xiaodong Zeng, Xiang Wang, Zhi Lai, L. Luo","doi":"10.1117/12.2180240","DOIUrl":"https://doi.org/10.1117/12.2180240","url":null,"abstract":"Based on the beam characteristics of semiconductor lasers, a new parameter for evaluating beam quality of semiconductor lasers is introduced. The shortcomings of M2 factor used in evaluating beam quality of semiconductor lasers are discussed and its limitations are pointed out. Moreover, some important aspects of the beam quality factor are discussed. The main factors to influence collimating the beam of semiconductor lasers are analyzed. Our results give us grounds to make the following conclusions: the new propagation parameter succeeds in its universality and adaptability.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"118 17","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120820582","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}
Y. Wang, Houmao Wang, Weihe Wang, Jian-Xi Fu, L. Fu
Aerosol Absorbing Index (AAI) can be used for the observation of the absorbing aerosol including dust, biomass burning and volcano ash etc. Recently, with much more aerosol pollution events occurring, atmospheric environment is getting worse in China. The AAI derived from FY-3/TOU has been used for the atmospheric aerosol pollution observation since 2013 by China Meteorological Administration. In this paper, the precision factors analysis of AAI retrieval from TOU is made. Based on the analysis, the wavelengths most suitable for AAI retrieval are 354 nm and 388 nm. Besides, considering the low spatial resolution of TOU (50×50 km2), a modified UV sensor is proposed with characters of much smaller size, higher sensitivity (SNR<4000) and higher spatial resolution (<5 km) which is much more suitable for observing aerosol pollution events, especially in urban areas.
{"title":"The modification of ultraviolet Total Ozone Unit (TOU) for absorbing aerosol index","authors":"Y. Wang, Houmao Wang, Weihe Wang, Jian-Xi Fu, L. Fu","doi":"10.1117/12.2179985","DOIUrl":"https://doi.org/10.1117/12.2179985","url":null,"abstract":"Aerosol Absorbing Index (AAI) can be used for the observation of the absorbing aerosol including dust, biomass burning and volcano ash etc. Recently, with much more aerosol pollution events occurring, atmospheric environment is getting worse in China. The AAI derived from FY-3/TOU has been used for the atmospheric aerosol pollution observation since 2013 by China Meteorological Administration. In this paper, the precision factors analysis of AAI retrieval from TOU is made. Based on the analysis, the wavelengths most suitable for AAI retrieval are 354 nm and 388 nm. Besides, considering the low spatial resolution of TOU (50×50 km2), a modified UV sensor is proposed with characters of much smaller size, higher sensitivity (SNR<4000) and higher spatial resolution (<5 km) which is much more suitable for observing aerosol pollution events, especially in urban areas.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128469806","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}
L. Ren, Chaobo Min, Jiannin Sun, Yan Gu, Feng Yang, Bo Zhu, J. Pan, Yiliang Guo
The design and imaging characteristic experiment of InGaAs shortwave infrared imaging system are introduced. Through the adoption of InGaAs focal plane array, the real time image process structure of InGaAs shortwave infrared imaging system is researched. The hardware circuit and image process software of the imaging system based on FPGA are researched. The InGaAs shortwave infrared imaging system is composed of shortwave infrared lens, InGaAs focal plane array, temperature controller module, power supply module, analog-to-digital converter module, digital-to-analog converter module, FPGA image processing module and optical-mechanical structure. The main lock frequency of InGaAs shortwave infrared imaging system is 30MHz. The output mode of the InGaAs shortwave infrared imaging system is PAL analog signal. The power dissipation of the imaging system is 2.6W. The real time signal process in InGaAs shortwave infrared imaging system includes non-uniformly correction algorithm, bad pixel replacement algorithm, and histogram equalization algorithm. Based on the InGaAs shortwave infrared imaging system, the imaging characteristic test of shortwave infrared is carried out for different targets in different conditions. In the foggy weather, the haze and fog penetration are tested. The InGaAs shortwave infrared imaging system could be used for observing humans, boats, architecture, and mountains in the haze and foggy weather. The configuration and performance of InGaAs shortwave infrared imaging system are respectively logical and steady. The research on the InGaAs shortwave infrared imaging system is worthwhile for improving the development of night vision technology.
{"title":"Research and experiment of InGaAs shortwave infrared imaging system based on FPGA","authors":"L. Ren, Chaobo Min, Jiannin Sun, Yan Gu, Feng Yang, Bo Zhu, J. Pan, Yiliang Guo","doi":"10.1117/12.2180226","DOIUrl":"https://doi.org/10.1117/12.2180226","url":null,"abstract":"The design and imaging characteristic experiment of InGaAs shortwave infrared imaging system are introduced. Through the adoption of InGaAs focal plane array, the real time image process structure of InGaAs shortwave infrared imaging system is researched. The hardware circuit and image process software of the imaging system based on FPGA are researched. The InGaAs shortwave infrared imaging system is composed of shortwave infrared lens, InGaAs focal plane array, temperature controller module, power supply module, analog-to-digital converter module, digital-to-analog converter module, FPGA image processing module and optical-mechanical structure. The main lock frequency of InGaAs shortwave infrared imaging system is 30MHz. The output mode of the InGaAs shortwave infrared imaging system is PAL analog signal. The power dissipation of the imaging system is 2.6W. The real time signal process in InGaAs shortwave infrared imaging system includes non-uniformly correction algorithm, bad pixel replacement algorithm, and histogram equalization algorithm. Based on the InGaAs shortwave infrared imaging system, the imaging characteristic test of shortwave infrared is carried out for different targets in different conditions. In the foggy weather, the haze and fog penetration are tested. The InGaAs shortwave infrared imaging system could be used for observing humans, boats, architecture, and mountains in the haze and foggy weather. The configuration and performance of InGaAs shortwave infrared imaging system are respectively logical and steady. The research on the InGaAs shortwave infrared imaging system is worthwhile for improving the development of night vision technology.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128154015","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}
We made quantitative detection analysis to infrared polarization characteristics of target using a non-real time infrared polarization detection system. First, the detection system must be calibrated, so according to our detection system, we presented a calibration method of doing radiometric calibration in four polarization detection channels. Second, based on the analysis of the infrared polarized mechanism, we made some theoretical simulation models. The target infrared radiation include spontaneous radiation and reflected radiation, and the combination of them lead to depolarization effect. The energy distribution between spontaneous and reflected radiation of the target is affected by target temperature, light conditions etc. So we created a experimental environment of low temperature and reflected radiation to validate theoretical model of spontaneous radiation, and found the experimental data has good consistency with theoretical prediction in a certain error range.
{"title":"The quantitative detection analysis to infrared polarization characteristics of targets","authors":"Jinyu Niu, Fanming Li","doi":"10.1117/12.2179551","DOIUrl":"https://doi.org/10.1117/12.2179551","url":null,"abstract":"We made quantitative detection analysis to infrared polarization characteristics of target using a non-real time infrared polarization detection system. First, the detection system must be calibrated, so according to our detection system, we presented a calibration method of doing radiometric calibration in four polarization detection channels. Second, based on the analysis of the infrared polarized mechanism, we made some theoretical simulation models. The target infrared radiation include spontaneous radiation and reflected radiation, and the combination of them lead to depolarization effect. The energy distribution between spontaneous and reflected radiation of the target is affected by target temperature, light conditions etc. So we created a experimental environment of low temperature and reflected radiation to validate theoretical model of spontaneous radiation, and found the experimental data has good consistency with theoretical prediction in a certain error range.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"9522 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129823375","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}
This paper describes how placement and routing with manual intervention to improve the digital signal performance. According to studying and analyzing the features of Field Programmable Gate Array (FPGA) devices which include chip architecture and timing characteristics, a new approach is presented that some key logic modules can be relocated reasonably with manual intervention after completing successful place-and-route automatically. An example is given to illustrate this method. In this example, in order to improve remote sensing Charge Coupled Device (CCD) camera performance, signal-skew and delays among CCD driving timing signals must be controlled accurately and easily. This method can make CCD driving timing signals obtain the zero-skew which means tCO (clock to out) values for all these signals are equal, and finally hardware tests are carried out and experiment results are measured precisely by oscilloscope.
{"title":"A novel approach to improve digital signal performance by placement and routing with manual intervention","authors":"Guimei Cheng, Songbo Wu, M. Wan, Bin Bao, J. Duan","doi":"10.1117/12.2179109","DOIUrl":"https://doi.org/10.1117/12.2179109","url":null,"abstract":"This paper describes how placement and routing with manual intervention to improve the digital signal performance. According to studying and analyzing the features of Field Programmable Gate Array (FPGA) devices which include chip architecture and timing characteristics, a new approach is presented that some key logic modules can be relocated reasonably with manual intervention after completing successful place-and-route automatically. An example is given to illustrate this method. In this example, in order to improve remote sensing Charge Coupled Device (CCD) camera performance, signal-skew and delays among CCD driving timing signals must be controlled accurately and easily. This method can make CCD driving timing signals obtain the zero-skew which means tCO (clock to out) values for all these signals are equal, and finally hardware tests are carried out and experiment results are measured precisely by oscilloscope.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130416856","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}
We investigative the field distribution in nanostructured metal waveguide arrays. Firstly, we analyze a simple discrete system containing two adjacent metallic waveguides (N=2). The propagation constants β1 and β2 can be calculated by a rigorous field analysis approach. According to the supermode theory of conventional dielectric waveguide arrays, we can also obtain the expressions of propagation constants. So we can obtain the coupling constant and the perturbation constant of the expressions in the supermode theory. Next, we consider a system that contains five adjacent metal waveguides (N=5). The propagation constants and the wavefunctions of the supermodes can be obtained according to the coupling constant, the perturbation constant, and the supermode theory. The incident light is located at the input of the 4st waveguide. The initial excited field can be expressed as a sum of supermodes. The total field is formed by the superposition of supermodes. The variation of field amplitude with propagation distance is obtained and can predict the precise positions of the field distribution. To demonstrate the analytical results, we numerically simulate the field distribution in the waveguides (N=5) constructed with silver by the finite-difference time-domain method. The numerical simulation results show a good agreement with theoretical expectations.
{"title":"The field distribution in a finite number of nanostructured metal waveguide arrays","authors":"X. Shi, Wu Yang, H. Xing, Xiaoshuang Chen","doi":"10.1117/12.2180521","DOIUrl":"https://doi.org/10.1117/12.2180521","url":null,"abstract":"We investigative the field distribution in nanostructured metal waveguide arrays. Firstly, we analyze a simple discrete system containing two adjacent metallic waveguides (N=2). The propagation constants β1 and β2 can be calculated by a rigorous field analysis approach. According to the supermode theory of conventional dielectric waveguide arrays, we can also obtain the expressions of propagation constants. So we can obtain the coupling constant and the perturbation constant of the expressions in the supermode theory. Next, we consider a system that contains five adjacent metal waveguides (N=5). The propagation constants and the wavefunctions of the supermodes can be obtained according to the coupling constant, the perturbation constant, and the supermode theory. The incident light is located at the input of the 4st waveguide. The initial excited field can be expressed as a sum of supermodes. The total field is formed by the superposition of supermodes. The variation of field amplitude with propagation distance is obtained and can predict the precise positions of the field distribution. To demonstrate the analytical results, we numerically simulate the field distribution in the waveguides (N=5) constructed with silver by the finite-difference time-domain method. The numerical simulation results show a good agreement with theoretical expectations.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127849733","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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