太赫兹扫描反射成像与实时透射成像的初步研究
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摘要
太赫兹辐射是频率在0.1THz~10THz区间内的远红外电磁辐射,它可以像X射线、可见光等辐射一样,作为物体成像的光源,由于其独特的性质,使得成像技术在安全检查、航天航空领域等方面都有着巨大的应用潜力。目前太赫兹源种类较多,但只有CO2激光泵浦THz激光器具有实验装置紧凑,输出光功率较大、功率较稳定等优点,且已经商品化。为此本论文主要是使用相干公司生产的CO2激光泵浦THz激光器SIFIR-50进行了两个方面的研究:一方面利用P4-42探测器进行了太赫兹扫描反射成像的研究,太赫兹反射成像在安全检测以及反恐等领域有很大的发展潜力,目前尚未见有国内相类似的研究报道;另一方面利用Pyrocom III热像仪进行了太赫兹实时透射成像的研究,目前提高太赫兹成像速度和图像分辨率是国际上对太赫兹成像研究的热点,利用Pyrocom III热像仪构建的实时透射成像系统在成像速度和图像分辨率上有很大的提高。
由于太赫兹扫描反射成像系统需要利用锗制分光镜,因此本论文首先研究了在太赫兹波段下半导体锗的透过特性,测得了在6种波长下的透过率,并且分析半导体锗的透过特性与波长之间的关系。
本文设计和搭建了太赫兹扫描反射成像系统,进行了改变系统参数对成像效果影响的实验,并且隔着障碍物对一些样品进行反射成像,为今后深入的研究和探索提供了一定的借鉴。另外,本文还搭建了基于Pyrocam III热像仪的实时透射成像系统,自行编写了系统的控制软件。利用该实时透射成像系统对1.63THz和2.52THz分别进行了成像实验研究。最后利用VC++初步编写了太赫兹仿真软件和太赫兹图像处理软件,为太赫兹成像在系统仿真和图像处理方面的研究打下基础。
THz radiation is the far infrared radiation whose frequency is between 0.1THz and 10THz, which can be used as imaging light source like X radiation and visible light. Because it has special characteristics, THz imaging technology has tremendous application potentiality in the safety inspection, aerospace and other areas. There are many THz laser sources, but only THz laser pumped by CO2 gas has the advantages of compactness, high and stable output power, which is already widely applied in commerce. In this thesis, the investigations on THz imaging were made in two aspects with CO2 laser-pumped THz laser produced by Coherent Corporation. On the one hand, the THz scanning reflection imaging technique was studied by utilizing the P4-42 detector. The THz reflection imaging has been not reported in domestic newspapers and periodicals at present, but it has tremendous application potentiality in safety inspection, counter-terrorism and other fields. On the other hand, the research on THz real-time transmission imaging was made by using the Pyrocam III thermal imaging system. In recent days, how to heighten the THz imaging velocity and resolution ratio is a focus in the international community, and the transmission imaging system based on Pyrocam III can be a good improvement measure of resolving these two issues.
Because the spectroscope made by spectroscope is used in the THz scanning reflection imaging system, the transmission properties of Ge semiconductor in Terahertz region were studied firstly. Transmittances at six different waveforms were measured and the relationship between the transmission and wavelength was investigated.
THz reflection imaging system was designed and implemented in this paper. Some imaging experiments were made to analyze how the parameters of system affect the imaging results, and some images were acquired by penetrating through some barriers, which would have some reference values for further research and exploration. Otherwise, the THz real-time transmission imaging system based on the Pyrocam III thermal imaging system was constructed, and the system control software was developed. Utilizing this THz real-time transmission imaging system, some imaging experiments were made at 1.63THz and 2.52THz. At last, the THz imaging simulation software and the THz image processing software were primarily designed utilizing VC++ tool, which would set the foundation for the research on THz imaging system simulation and image processing.
由于太赫兹扫描反射成像系统需要利用锗制分光镜,因此本论文首先研究了在太赫兹波段下半导体锗的透过特性,测得了在6种波长下的透过率,并且分析半导体锗的透过特性与波长之间的关系。
本文设计和搭建了太赫兹扫描反射成像系统,进行了改变系统参数对成像效果影响的实验,并且隔着障碍物对一些样品进行反射成像,为今后深入的研究和探索提供了一定的借鉴。另外,本文还搭建了基于Pyrocam III热像仪的实时透射成像系统,自行编写了系统的控制软件。利用该实时透射成像系统对1.63THz和2.52THz分别进行了成像实验研究。最后利用VC++初步编写了太赫兹仿真软件和太赫兹图像处理软件,为太赫兹成像在系统仿真和图像处理方面的研究打下基础。
THz radiation is the far infrared radiation whose frequency is between 0.1THz and 10THz, which can be used as imaging light source like X radiation and visible light. Because it has special characteristics, THz imaging technology has tremendous application potentiality in the safety inspection, aerospace and other areas. There are many THz laser sources, but only THz laser pumped by CO2 gas has the advantages of compactness, high and stable output power, which is already widely applied in commerce. In this thesis, the investigations on THz imaging were made in two aspects with CO2 laser-pumped THz laser produced by Coherent Corporation. On the one hand, the THz scanning reflection imaging technique was studied by utilizing the P4-42 detector. The THz reflection imaging has been not reported in domestic newspapers and periodicals at present, but it has tremendous application potentiality in safety inspection, counter-terrorism and other fields. On the other hand, the research on THz real-time transmission imaging was made by using the Pyrocam III thermal imaging system. In recent days, how to heighten the THz imaging velocity and resolution ratio is a focus in the international community, and the transmission imaging system based on Pyrocam III can be a good improvement measure of resolving these two issues.
Because the spectroscope made by spectroscope is used in the THz scanning reflection imaging system, the transmission properties of Ge semiconductor in Terahertz region were studied firstly. Transmittances at six different waveforms were measured and the relationship between the transmission and wavelength was investigated.
THz reflection imaging system was designed and implemented in this paper. Some imaging experiments were made to analyze how the parameters of system affect the imaging results, and some images were acquired by penetrating through some barriers, which would have some reference values for further research and exploration. Otherwise, the THz real-time transmission imaging system based on the Pyrocam III thermal imaging system was constructed, and the system control software was developed. Utilizing this THz real-time transmission imaging system, some imaging experiments were made at 1.63THz and 2.52THz. At last, the THz imaging simulation software and the THz image processing software were primarily designed utilizing VC++ tool, which would set the foundation for the research on THz imaging system simulation and image processing.
引文
1贾刚,汪力,张希成.太赫兹波(TeraHertz)科学与技术.中国科学资金. 2002, 4: 200~202
2 Bradley Ferguson,张希成.太赫兹科学于技术研究回顾.物理. 2003, 32(5): 286~293
3黄江平.高温超导公外探测器的应用及发展前景.低温工程. 1999. (4): 292~296
4曹俊诚.太赫兹辐射源与探测器研究进展.功能材料与器件学报,2003,9(2): 111~117
5 Z. W. Zhang, Y. Zhang, G. Z. Zhao et al. Terahertz Time-Domain Spectroscopy for Explosive Imaging. Optik-International Journal for Light and Electron Optics. 2007, 118(7):325~329
6 J. F. Federici, S. Brian, H. Fen et al. THz Imaging and Sensing for Security Applications. Semiconductor Science and Technology. 2005, 20(7):266~280
7 P. C. M. MPlanken, C E W M Van Rijmenam, R N Schouten et al. Opto-Electronic Pulsed THz Systems. Semiconductor Science and Technology. 2005, 20(7):121~127
8 B. Ferguson, S. Wang, D. Gray et al. Identification of Biological Tissue Using Chirped Probe THz Imaging. Microeled Tronics Journal. 2002, 33(12): 1043~1051
9 P. H. Bolivar, M. Brucherseifer, M. Nagel et al. Label-Free Sensing of Genetic Sequences with Integrated Terahertz Systems. Annual International Conference of the IEEE Engineer in Medicine and Biology-Proceedings. 2002, (3):2331~2332
10 V. P. Wallace, R. M. Woodward, A. J. Fitzgerald et al. Terahertz Pulsed Imaging of Cancers. The International Society for Optical Engineering. 2003, (4949):353~359
11 A. J. Fitzqerald, E. Berry, N. N. Zinovev et al. An Introduction to Medical Imaging with Coherent Terahertz Frequency Radiation. Physics in Medicine and Biology. 2002, 47(7):67~84
12 M. Jeannette. Harnessing THz for Medical Applications. Emerging-Technologies. 2003. 45(10):28~30
13 A. Bressan, L. Silva, G. L. Granato et al. Far Infrared and Radio Emission in Dusty Starburst galaxies. Astronomy and Astrophysics. 2002, 392(2):377~391
14 S. Hanany, D. P. Marrone. Comparison of Designs of Off-Axis Gregorian Telescopes for Millimeter-Wave Large Focal-Plane Arrays. Applied Optics. 2002, 41(22):4666~4670
15陈文新.用于静止气象卫星的亚毫米波探测器初探.空间电子技术. 2003, (3):29~33
16 J. F. Federici, Brian Schulkin, Feng Huang, et al. THz Imaging and Sensing for Security Applications. Semiconductor Science and Technology. 2005, 20:266~280
17 P. C. M. Planken, C. E. W. M. wan Rijmenam, R. N. Schouten. Opto-electronic Pulsed THz Systems. Semiconductor science and technology. 2005, (20): 121~127
18 B. Ferguson, S. Wang, D. Gray. Identification of Biological Tissue Using Chirped Probe THz Imaging. Microeledtronics Journal. 2002. (33): 1043~1051
19 A. Doria, G. P. Gallerano, E. Giovenale, et al. THz Radiation Studies on Biological Systems at the ENEA FEL Facility. Infrared Physics and Technology. 2004, 45(5): 339~347
20 J. S. Slivken, S. Evans, A. Doris. High Power CW Operation of a 6μm quantum cascade laser at room temperature. Appl Phys Lett. 2003, (83): 2503
21 Kurt J. Linden, William R. Neal. Terahertz Laser Based Standoff Imaging System. IEEE 2005: 31~44
22施卫,张显斌,贾婉丽.用飞秒激光出发GaAs光电导体产生THz电磁波的研究.半导体学报. 2005, 25(12):1735~1738
23 Y. Q. Lu, M. Xiao, G. J. Gregory et al. Coherent Microwave Generation in a Nonlinear Photonic Crystal. IEEE Journal of Quantum Electronics. 2002, 38(5):481~485
24李锐,顾春明,贺莉蓉. ZnTe晶体中光学整流产生的THz辐射及其光电探测研究.物理学报. 2004, 53(4): 1217~1222
25 S. Bhattacharjee, J. H. Booske, C. L. Kory et al. THz Radiation Using Compact Folded Waveguide TWT Oscillators. IEEE MTT-S International Microwave Symposium Digest. 2003, (2):1331~1334
26 A. Maestrini, J. Ward, J. Gill et al. A 1.7-1.9 THz Local Oscillator Source. Microwave and Wireless Components Letters. 2004, 14(6):253~255
27 S. Krishnagopal, V. Kumar. Free-Electron Lasers. Radiation Physics and Chemistry. 2004, 70(4-5):559~569
28 N. G. Gavrilov, B. A. Knyazev, E. I. Kolobanov et al. Status of the Novosibirsk High-Power Terahertz FEL. Nuclear Instruments and Methods in Physics Research Section A: Accelerators. Spectrometers. Detectors and Associated Equipment. 2007, 575(1-2):54~57
29 G. R. Neil, C. Behre, S. V. Benson et al. The JLab High Power ERL light source. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 2006, 557(1):9~15
30 A. Tredicucci, R. K?hler, F. Beltram et al. Terahertz Quantum Cascade Lasers. Physics E: Low-Dimensional Systems and Nanostructures. 2004, 21(2-4):846~851
31 D. S. Citrin. High-Field Electron-Hole Wavepacket Dynamics and THz Emission in Semiconductor Quantum Wells. Optics Communications. 1998, 148(1-3):187~196
32 E. M. Telles, H. Odashima, L. R. Zink et al. Optically Pumped FIR Laser Lines from CH3OH: New Laser Lines, Frequency Measurements, and Assignments. Journal of Molecular Spectroscopy. 1999, 195(2):360~366
33 Young Uk Jeong,Grigori M.Kazakevitch, et al. Application of a Wide-band Compact FEL on THz Imaging. Nuclear Instrument and Methods in Physics Research A. 2005: 90~95
34 V.S. Cherkassky, B.A. Knyazev, V.V. Kubarev, et al. Imaging Techniques for a High-power THz Free Electron Laser. Nuclear Instruments and Methods in Physics Research A, 2005, 543(1): 102~109
35 Hua Zhong ,Nick Karpowicz“Teraherz Wave Imaging for Landmine Detections”, Terahertz for Military and Security ApplicationⅥ, Proceedings of SPIE ,2004,(5411): 31~44
36 Jason C. Dickinson, Thomas M. Goyette, High Resolution Imaging using 325GHz and 1.5THz Transceivers, Proceedings of the Fifteenth International Symposium on Space Terahertz Technology, 2004: 30~42
37 Jason C.Dickinson, Thomas M.Goyette Teraherz imaging of subjects with concealed weapons, Terahertz for Military and Security ApplicationⅥ, Proceedings of SPIE 2006, 6212(1): 13~20
38 Iason C.Dickinson, Thomas M.Goyette, Jerry Waldman. High Resolution Imaging Using 325GHz and 1.5THz Transceivers. Processing of the Fifteenth International Symposium on Space Teraherz Techology, 2004, 373~380.
39 Caihong Zhang, Yuanyuan Wang, Jian Chen, et al. Continuous-wave Terahertz Imaging System Based on Far-infraed Laser Source. Conference digest of the 2006 joint 31st international conference on infrared and millimeter waves and
14th international conference on terahertz electronics. 2006: 426~430
40张敏,阮双琛,杨珺.连续太赫兹波实时透射成像实验研究.深圳大学学报理工版, 2007, 24(4): 384~386
41迟欣,太赫兹激光透射成像技术初步研究,哈尔滨工业大学硕士论文, 2007: 49~58
42 W. Lanigan, E. Butler, E. Duffy, et al. Analysis of Millimeter-wave Imaging and Detection. Proc. of SPIE. 2006, 6472:1~9
43黄呈辉,黄见洪,张戈.一种精确计算光学材料吸收系数的方法.激光杂志, 2001, 22(6), 45~46
44 J.E.Peters, P.D.Ownby. Far Infrared Abosorption of Czochralski Germanium and Silicon. SPIE, 1998, 34(24): 98~105
45 Ernest V. Loewenstein, Donald R. Smith, Optical Constants of Far Infrared Materials.2: Crystalline Solids. Apply Optic, 1973, 12(2): 398~406
46汪月松.光电技术与实验.北京理工大学出版社, 2000:153~170
47王志,侯峙云,刘宝华.热释电红外探测器综合性能参数的测试.红外技术. 2002, 24(3):41~43
48李琦,迟欣.聚四氟乙烯材料的THz吸收特性实验研究.中国激光.2008, 35(2): 756~759.
49张敏,阮双琛,杨珺.太赫兹成像控制软件设计.微计算机信息. 2007, 23(11):25~27
50 Rafael C. Conzalez, Richard E. Woods.数字图像处理.阮秋琦,阮宇智.第二版,电子工业出版社. 2006:175~183
2 Bradley Ferguson,张希成.太赫兹科学于技术研究回顾.物理. 2003, 32(5): 286~293
3黄江平.高温超导公外探测器的应用及发展前景.低温工程. 1999. (4): 292~296
4曹俊诚.太赫兹辐射源与探测器研究进展.功能材料与器件学报,2003,9(2): 111~117
5 Z. W. Zhang, Y. Zhang, G. Z. Zhao et al. Terahertz Time-Domain Spectroscopy for Explosive Imaging. Optik-International Journal for Light and Electron Optics. 2007, 118(7):325~329
6 J. F. Federici, S. Brian, H. Fen et al. THz Imaging and Sensing for Security Applications. Semiconductor Science and Technology. 2005, 20(7):266~280
7 P. C. M. MPlanken, C E W M Van Rijmenam, R N Schouten et al. Opto-Electronic Pulsed THz Systems. Semiconductor Science and Technology. 2005, 20(7):121~127
8 B. Ferguson, S. Wang, D. Gray et al. Identification of Biological Tissue Using Chirped Probe THz Imaging. Microeled Tronics Journal. 2002, 33(12): 1043~1051
9 P. H. Bolivar, M. Brucherseifer, M. Nagel et al. Label-Free Sensing of Genetic Sequences with Integrated Terahertz Systems. Annual International Conference of the IEEE Engineer in Medicine and Biology-Proceedings. 2002, (3):2331~2332
10 V. P. Wallace, R. M. Woodward, A. J. Fitzgerald et al. Terahertz Pulsed Imaging of Cancers. The International Society for Optical Engineering. 2003, (4949):353~359
11 A. J. Fitzqerald, E. Berry, N. N. Zinovev et al. An Introduction to Medical Imaging with Coherent Terahertz Frequency Radiation. Physics in Medicine and Biology. 2002, 47(7):67~84
12 M. Jeannette. Harnessing THz for Medical Applications. Emerging-Technologies. 2003. 45(10):28~30
13 A. Bressan, L. Silva, G. L. Granato et al. Far Infrared and Radio Emission in Dusty Starburst galaxies. Astronomy and Astrophysics. 2002, 392(2):377~391
14 S. Hanany, D. P. Marrone. Comparison of Designs of Off-Axis Gregorian Telescopes for Millimeter-Wave Large Focal-Plane Arrays. Applied Optics. 2002, 41(22):4666~4670
15陈文新.用于静止气象卫星的亚毫米波探测器初探.空间电子技术. 2003, (3):29~33
16 J. F. Federici, Brian Schulkin, Feng Huang, et al. THz Imaging and Sensing for Security Applications. Semiconductor Science and Technology. 2005, 20:266~280
17 P. C. M. Planken, C. E. W. M. wan Rijmenam, R. N. Schouten. Opto-electronic Pulsed THz Systems. Semiconductor science and technology. 2005, (20): 121~127
18 B. Ferguson, S. Wang, D. Gray. Identification of Biological Tissue Using Chirped Probe THz Imaging. Microeledtronics Journal. 2002. (33): 1043~1051
19 A. Doria, G. P. Gallerano, E. Giovenale, et al. THz Radiation Studies on Biological Systems at the ENEA FEL Facility. Infrared Physics and Technology. 2004, 45(5): 339~347
20 J. S. Slivken, S. Evans, A. Doris. High Power CW Operation of a 6μm quantum cascade laser at room temperature. Appl Phys Lett. 2003, (83): 2503
21 Kurt J. Linden, William R. Neal. Terahertz Laser Based Standoff Imaging System. IEEE 2005: 31~44
22施卫,张显斌,贾婉丽.用飞秒激光出发GaAs光电导体产生THz电磁波的研究.半导体学报. 2005, 25(12):1735~1738
23 Y. Q. Lu, M. Xiao, G. J. Gregory et al. Coherent Microwave Generation in a Nonlinear Photonic Crystal. IEEE Journal of Quantum Electronics. 2002, 38(5):481~485
24李锐,顾春明,贺莉蓉. ZnTe晶体中光学整流产生的THz辐射及其光电探测研究.物理学报. 2004, 53(4): 1217~1222
25 S. Bhattacharjee, J. H. Booske, C. L. Kory et al. THz Radiation Using Compact Folded Waveguide TWT Oscillators. IEEE MTT-S International Microwave Symposium Digest. 2003, (2):1331~1334
26 A. Maestrini, J. Ward, J. Gill et al. A 1.7-1.9 THz Local Oscillator Source. Microwave and Wireless Components Letters. 2004, 14(6):253~255
27 S. Krishnagopal, V. Kumar. Free-Electron Lasers. Radiation Physics and Chemistry. 2004, 70(4-5):559~569
28 N. G. Gavrilov, B. A. Knyazev, E. I. Kolobanov et al. Status of the Novosibirsk High-Power Terahertz FEL. Nuclear Instruments and Methods in Physics Research Section A: Accelerators. Spectrometers. Detectors and Associated Equipment. 2007, 575(1-2):54~57
29 G. R. Neil, C. Behre, S. V. Benson et al. The JLab High Power ERL light source. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 2006, 557(1):9~15
30 A. Tredicucci, R. K?hler, F. Beltram et al. Terahertz Quantum Cascade Lasers. Physics E: Low-Dimensional Systems and Nanostructures. 2004, 21(2-4):846~851
31 D. S. Citrin. High-Field Electron-Hole Wavepacket Dynamics and THz Emission in Semiconductor Quantum Wells. Optics Communications. 1998, 148(1-3):187~196
32 E. M. Telles, H. Odashima, L. R. Zink et al. Optically Pumped FIR Laser Lines from CH3OH: New Laser Lines, Frequency Measurements, and Assignments. Journal of Molecular Spectroscopy. 1999, 195(2):360~366
33 Young Uk Jeong,Grigori M.Kazakevitch, et al. Application of a Wide-band Compact FEL on THz Imaging. Nuclear Instrument and Methods in Physics Research A. 2005: 90~95
34 V.S. Cherkassky, B.A. Knyazev, V.V. Kubarev, et al. Imaging Techniques for a High-power THz Free Electron Laser. Nuclear Instruments and Methods in Physics Research A, 2005, 543(1): 102~109
35 Hua Zhong ,Nick Karpowicz“Teraherz Wave Imaging for Landmine Detections”, Terahertz for Military and Security ApplicationⅥ, Proceedings of SPIE ,2004,(5411): 31~44
36 Jason C. Dickinson, Thomas M. Goyette, High Resolution Imaging using 325GHz and 1.5THz Transceivers, Proceedings of the Fifteenth International Symposium on Space Terahertz Technology, 2004: 30~42
37 Jason C.Dickinson, Thomas M.Goyette Teraherz imaging of subjects with concealed weapons, Terahertz for Military and Security ApplicationⅥ, Proceedings of SPIE 2006, 6212(1): 13~20
38 Iason C.Dickinson, Thomas M.Goyette, Jerry Waldman. High Resolution Imaging Using 325GHz and 1.5THz Transceivers. Processing of the Fifteenth International Symposium on Space Teraherz Techology, 2004, 373~380.
39 Caihong Zhang, Yuanyuan Wang, Jian Chen, et al. Continuous-wave Terahertz Imaging System Based on Far-infraed Laser Source. Conference digest of the 2006 joint 31st international conference on infrared and millimeter waves and
14th international conference on terahertz electronics. 2006: 426~430
40张敏,阮双琛,杨珺.连续太赫兹波实时透射成像实验研究.深圳大学学报理工版, 2007, 24(4): 384~386
41迟欣,太赫兹激光透射成像技术初步研究,哈尔滨工业大学硕士论文, 2007: 49~58
42 W. Lanigan, E. Butler, E. Duffy, et al. Analysis of Millimeter-wave Imaging and Detection. Proc. of SPIE. 2006, 6472:1~9
43黄呈辉,黄见洪,张戈.一种精确计算光学材料吸收系数的方法.激光杂志, 2001, 22(6), 45~46
44 J.E.Peters, P.D.Ownby. Far Infrared Abosorption of Czochralski Germanium and Silicon. SPIE, 1998, 34(24): 98~105
45 Ernest V. Loewenstein, Donald R. Smith, Optical Constants of Far Infrared Materials.2: Crystalline Solids. Apply Optic, 1973, 12(2): 398~406
46汪月松.光电技术与实验.北京理工大学出版社, 2000:153~170
47王志,侯峙云,刘宝华.热释电红外探测器综合性能参数的测试.红外技术. 2002, 24(3):41~43
48李琦,迟欣.聚四氟乙烯材料的THz吸收特性实验研究.中国激光.2008, 35(2): 756~759.
49张敏,阮双琛,杨珺.太赫兹成像控制软件设计.微计算机信息. 2007, 23(11):25~27
50 Rafael C. Conzalez, Richard E. Woods.数字图像处理.阮秋琦,阮宇智.第二版,电子工业出版社. 2006:175~183