Pub Date : 2000-09-10DOI: 10.1109/CLEOE.2000.910088
Y. Zhou, P. A. Snow, P. Russell
Summary form only given. There is substantial interest in obtaining light emission in silicon at wavelengths away from 750 nm porous silicon (p-Si) emission band. Erbium ions, incorporated into sponge-like structure of p-Si, can produce light emission at 1540 nm. We report for the first time light emission from a multilayer porous silicon microcavity, into which the Er-ions were doped electrochemically as luminescence centres.
{"title":"Light emission from erbium-doped multilayer porous silicon microcavity","authors":"Y. Zhou, P. A. Snow, P. Russell","doi":"10.1109/CLEOE.2000.910088","DOIUrl":"https://doi.org/10.1109/CLEOE.2000.910088","url":null,"abstract":"Summary form only given. There is substantial interest in obtaining light emission in silicon at wavelengths away from 750 nm porous silicon (p-Si) emission band. Erbium ions, incorporated into sponge-like structure of p-Si, can produce light emission at 1540 nm. We report for the first time light emission from a multilayer porous silicon microcavity, into which the Er-ions were doped electrochemically as luminescence centres.","PeriodicalId":250878,"journal":{"name":"Conference Digest. 2000 Conference on Lasers and Electro-Optics Europe (Cat. No.00TH8505)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122876538","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 : 2000-09-10DOI: 10.1109/CLEOE.2000.910099
E. Avrutin
Summary form only. Homogeneous broadening of a radiative transition in a semiconductor plays an important part in understanding and modelling optical properties of semiconductor lasers and optical amplifiers (as well as LEDs, modulators and photodetectors). This broadening is described by means of the lineshape function L(/spl delta/)=L'(/spl delta/)+iL''(/spl delta/) (/spl delta/=h/spl omega/-E/sub x/ being the detuning between the energy of the emitted photon and the energy separation of the e'-h/sup +/ pair involved in the act of emission).
{"title":"A simple analytical non-Lorentzian approximation for the complex lineshape function for semiconductor laser modelling","authors":"E. Avrutin","doi":"10.1109/CLEOE.2000.910099","DOIUrl":"https://doi.org/10.1109/CLEOE.2000.910099","url":null,"abstract":"Summary form only. Homogeneous broadening of a radiative transition in a semiconductor plays an important part in understanding and modelling optical properties of semiconductor lasers and optical amplifiers (as well as LEDs, modulators and photodetectors). This broadening is described by means of the lineshape function L(/spl delta/)=L'(/spl delta/)+iL''(/spl delta/) (/spl delta/=h/spl omega/-E/sub x/ being the detuning between the energy of the emitted photon and the energy separation of the e'-h/sup +/ pair involved in the act of emission).","PeriodicalId":250878,"journal":{"name":"Conference Digest. 2000 Conference on Lasers and Electro-Optics Europe (Cat. No.00TH8505)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114148803","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 : 2000-09-10DOI: 10.1109/CLEOE.2000.910307
A. Mugnier, V. Kermene, A. Barthélémy
Summary form only. During the past years high-energy, nanosecond OPOs have been the subject of numerous investigations because of their potential applications as powerful tunable sources. However, they require short cavity length to achieve high conversion efficiency and large pump cross-section to avoid optical damages. Typical cavities correspond to high Fresnel number and produce beams of bad spatial quality. An increase in OPO output energy frequently leads to a reduction in OPO brightness. We propose a new method based on spatio-temporal shaping of the pump wave to improve the transverse properties of OPO emission at high energy level. Extracavity optical parametric generation is usually performed in two steps (at least). The pump pulse is split in two parts of unequal intensity. The weakest pulse, once confined in a tightly focused beam serves for the actual OPG, while the pulse of high energy is used for amplification during a second pass through the nonlinear crystal. This permits most of the times to preserve a good beam profile. The same idea has been applied to OPO. At the beginning of the pumping the pump beam size is chosen to be small enough to ensure a transverse single mode oscillation in the cavity and energetic enough to start the oscillation. Then the following part of the pump beam, bringing the main part of the energy, is spread on a larger cross section to amplify the oscillating wave.
{"title":"Improvement of pulsed optical parametric oscillator by spatio-temporal shaping of the pump beam","authors":"A. Mugnier, V. Kermene, A. Barthélémy","doi":"10.1109/CLEOE.2000.910307","DOIUrl":"https://doi.org/10.1109/CLEOE.2000.910307","url":null,"abstract":"Summary form only. During the past years high-energy, nanosecond OPOs have been the subject of numerous investigations because of their potential applications as powerful tunable sources. However, they require short cavity length to achieve high conversion efficiency and large pump cross-section to avoid optical damages. Typical cavities correspond to high Fresnel number and produce beams of bad spatial quality. An increase in OPO output energy frequently leads to a reduction in OPO brightness. We propose a new method based on spatio-temporal shaping of the pump wave to improve the transverse properties of OPO emission at high energy level. Extracavity optical parametric generation is usually performed in two steps (at least). The pump pulse is split in two parts of unequal intensity. The weakest pulse, once confined in a tightly focused beam serves for the actual OPG, while the pulse of high energy is used for amplification during a second pass through the nonlinear crystal. This permits most of the times to preserve a good beam profile. The same idea has been applied to OPO. At the beginning of the pumping the pump beam size is chosen to be small enough to ensure a transverse single mode oscillation in the cavity and energetic enough to start the oscillation. Then the following part of the pump beam, bringing the main part of the energy, is spread on a larger cross section to amplify the oscillating wave.","PeriodicalId":250878,"journal":{"name":"Conference Digest. 2000 Conference on Lasers and Electro-Optics Europe (Cat. No.00TH8505)","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114183720","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 : 2000-09-10DOI: 10.1109/CLEOE.2000.910089
I. Khmyrova, N. Tsutsui, V. Ryzhii, T. Ikegami
Summary form only given. Photon recycling associated with the reabsorption of trapped photons strongly affects the performance of light emitting diodes (LEDs). It significantly enhances the LED external quantum efficiency. We use a phenomenological model of the electron and photon transport to calculate characteristics of LEDs with nonuniform injection taking into account the effect of photon recycling. We consider double heterostructure LEDs with a narrow-gap p-doped active region clad between two wide-gap confining layers. The LED structure has a strip top contact injecting electrons and a wide bottom contact injecting holes. Due to the relatively small area of one of the contacts, the electron injection is pronouncedly nonuniform. The bottom of the LED is provided with a mirror.
{"title":"Influence of photon recycling on the performance of light emitting diodes with nonuniform injection","authors":"I. Khmyrova, N. Tsutsui, V. Ryzhii, T. Ikegami","doi":"10.1109/CLEOE.2000.910089","DOIUrl":"https://doi.org/10.1109/CLEOE.2000.910089","url":null,"abstract":"Summary form only given. Photon recycling associated with the reabsorption of trapped photons strongly affects the performance of light emitting diodes (LEDs). It significantly enhances the LED external quantum efficiency. We use a phenomenological model of the electron and photon transport to calculate characteristics of LEDs with nonuniform injection taking into account the effect of photon recycling. We consider double heterostructure LEDs with a narrow-gap p-doped active region clad between two wide-gap confining layers. The LED structure has a strip top contact injecting electrons and a wide bottom contact injecting holes. Due to the relatively small area of one of the contacts, the electron injection is pronouncedly nonuniform. The bottom of the LED is provided with a mirror.","PeriodicalId":250878,"journal":{"name":"Conference Digest. 2000 Conference on Lasers and Electro-Optics Europe (Cat. No.00TH8505)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116626450","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 : 2000-09-10DOI: 10.1109/CLEOE.2000.909949
M. Fermann, B. Thomsen, V. Kruglov, J. Dudley, J. Harvey
Summary form only given. The amplification of ultrashort pulses to high powers in optical fiber amplifiers is usually associated with severe pulse distortion due to optical wave-breaking, limiting the usefulness of such amplifiers in ultrafast optics. For sufficiently high gain, however, an incident ultrashort pulse in a fiber amplifier with normal dispersion evolves into a a parabolic pulse which propagates in a wave-breaking free manner. Here, we report the first experimental generation and characterization of such parabolic pulses using frequency-resolved optical gating (FROG). The pulses retain their parabolic profile after self-similar propagation in standard fiber and are compressed to 70 fs pulses with 80 kW peak power.
{"title":"Propagation and compression of high power parabolic pulses generated in a high gain Yb:doped fibre amplifier","authors":"M. Fermann, B. Thomsen, V. Kruglov, J. Dudley, J. Harvey","doi":"10.1109/CLEOE.2000.909949","DOIUrl":"https://doi.org/10.1109/CLEOE.2000.909949","url":null,"abstract":"Summary form only given. The amplification of ultrashort pulses to high powers in optical fiber amplifiers is usually associated with severe pulse distortion due to optical wave-breaking, limiting the usefulness of such amplifiers in ultrafast optics. For sufficiently high gain, however, an incident ultrashort pulse in a fiber amplifier with normal dispersion evolves into a a parabolic pulse which propagates in a wave-breaking free manner. Here, we report the first experimental generation and characterization of such parabolic pulses using frequency-resolved optical gating (FROG). The pulses retain their parabolic profile after self-similar propagation in standard fiber and are compressed to 70 fs pulses with 80 kW peak power.","PeriodicalId":250878,"journal":{"name":"Conference Digest. 2000 Conference on Lasers and Electro-Optics Europe (Cat. No.00TH8505)","volume":"20 19-20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116722362","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 : 2000-09-10DOI: 10.1109/CLEOE.2000.910404
V. Wesemann, G. Bitz, J. L’huillier, A. Borsutzky, R. Wallenstein
Summary form only given. The optical quality of laser active crystals is of fundamental importance for the development of efficient and reliable laser systems. Up to now the correlation between the optical properties of the laser crystal and the laser performance has not been investigated in detail. To examine the relation between the optical properties and the laser performance we measured, with high spatial resolution and high precision, optical properties such as doping concentration, optical homogeneity and stress induced birefringence. The local values of these parameters are compared with the corresponding laser performance in respect to threshold and slope efficiency. The crystal investigated was Nd:YAG.
{"title":"Spatially two-dimensional resolved characterisation of Nd:YAG boule slices","authors":"V. Wesemann, G. Bitz, J. L’huillier, A. Borsutzky, R. Wallenstein","doi":"10.1109/CLEOE.2000.910404","DOIUrl":"https://doi.org/10.1109/CLEOE.2000.910404","url":null,"abstract":"Summary form only given. The optical quality of laser active crystals is of fundamental importance for the development of efficient and reliable laser systems. Up to now the correlation between the optical properties of the laser crystal and the laser performance has not been investigated in detail. To examine the relation between the optical properties and the laser performance we measured, with high spatial resolution and high precision, optical properties such as doping concentration, optical homogeneity and stress induced birefringence. The local values of these parameters are compared with the corresponding laser performance in respect to threshold and slope efficiency. The crystal investigated was Nd:YAG.","PeriodicalId":250878,"journal":{"name":"Conference Digest. 2000 Conference on Lasers and Electro-Optics Europe (Cat. No.00TH8505)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129756834","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 : 2000-09-10DOI: 10.1109/CLEOE.2000.909779
M. Nagele, D. Hofstetter, J. Faist, M. Sigrist
Summary form only given. The development and application of a mobile laser-photoacoustic spectrometer for in-situ multicomponent monitoring of trace gases in different environments is reported. Sub-ppbV (<10/sup -9/ per volume)-concentrations can be measured with a novel resonant multipass photoacoustic cell. For ethene (C/sub 2/H/sub 4/) buffered in synthetic air a minimum detection limit of 70 pptV (70/spl times/10/sup -12/ per volume) is achieved with a line-tunable CO/sub 2/-laser as pump source corresponding to a minimum measurable absorption coefficient /spl alpha//sub min/=2/spl times/10/sup -9/ cm/sup -1/ for a signal-to-noise ratio of 3. The multicomponent capability of the system is demonstrated with continuous sequential measurements of gases such as ethene, methanol, and ethanol of air from a fruit storage chamber.
{"title":"Mobile laser photoacoustic spectrometer for multicomponent trace-gas monitoring based on CO/sub 2/- and quantum-cascade lasers as pump sources","authors":"M. Nagele, D. Hofstetter, J. Faist, M. Sigrist","doi":"10.1109/CLEOE.2000.909779","DOIUrl":"https://doi.org/10.1109/CLEOE.2000.909779","url":null,"abstract":"Summary form only given. The development and application of a mobile laser-photoacoustic spectrometer for in-situ multicomponent monitoring of trace gases in different environments is reported. Sub-ppbV (<10/sup -9/ per volume)-concentrations can be measured with a novel resonant multipass photoacoustic cell. For ethene (C/sub 2/H/sub 4/) buffered in synthetic air a minimum detection limit of 70 pptV (70/spl times/10/sup -12/ per volume) is achieved with a line-tunable CO/sub 2/-laser as pump source corresponding to a minimum measurable absorption coefficient /spl alpha//sub min/=2/spl times/10/sup -9/ cm/sup -1/ for a signal-to-noise ratio of 3. The multicomponent capability of the system is demonstrated with continuous sequential measurements of gases such as ethene, methanol, and ethanol of air from a fruit storage chamber.","PeriodicalId":250878,"journal":{"name":"Conference Digest. 2000 Conference on Lasers and Electro-Optics Europe (Cat. No.00TH8505)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128283824","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 : 2000-09-10DOI: 10.1109/CLEOE.2000.910320
R. Dorn, S. Quabis, O. Glockl, M. Eberler, G. Leuchs
Summary form only. A reduction of the focal area in an optical system with high numerical aperture call be reached if one takes advantage of the polarization distribution of the focused beam. Numerical calculations were performed for a linearly and a radially polarized field distribution considering different intensity distributions. Especially. When an annular aperture is used, the focal area of a radially polarized input beam can be reduced by about a factor of two compared to a linearly polarized beam. The well known phenomenon of increased sidelobes can also be suppressed when rising a radially polarized beam.
{"title":"Reduction of the focal spot size by using polarization effects","authors":"R. Dorn, S. Quabis, O. Glockl, M. Eberler, G. Leuchs","doi":"10.1109/CLEOE.2000.910320","DOIUrl":"https://doi.org/10.1109/CLEOE.2000.910320","url":null,"abstract":"Summary form only. A reduction of the focal area in an optical system with high numerical aperture call be reached if one takes advantage of the polarization distribution of the focused beam. Numerical calculations were performed for a linearly and a radially polarized field distribution considering different intensity distributions. Especially. When an annular aperture is used, the focal area of a radially polarized input beam can be reduced by about a factor of two compared to a linearly polarized beam. The well known phenomenon of increased sidelobes can also be suppressed when rising a radially polarized beam.","PeriodicalId":250878,"journal":{"name":"Conference Digest. 2000 Conference on Lasers and Electro-Optics Europe (Cat. No.00TH8505)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128351910","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 : 2000-09-10DOI: 10.1109/CLEOE.2000.909695
R. Grasso, J.E. Ackleson, C. G. Stimson, C. M. Vann, J. W. Buckle, C.P. Pratty, J. A. Haigh, W.R. Pommeroy, S. Price, M. Roberts
Summary form only given. Northrop Grumman (US) and Defense Evaluation and Research Agency (DERA) (UK) report upon a program to characterize the performance of its (OASYS) Obstacle Avoidance Imaging Laser Radar System against various terrestrial targets. High resolution laser radar images of various naturally occurring and manmade terrestrial objects were obtained and their properties measured. These objects include 1) wires of various diameter and reflectivity, 2) trees and vegetation, 3) large and small vertical objects including transmission towers and poles, 4) buildings and structures, and 5) various terrain types. OASYS can discriminate and identify objects against a complementary background. This allows realization of objects that cannot otherwise be seen using other active and passive detection systems.
{"title":"Imaging laser radar performance assessment against various naturally occurring and manmade terrestrial objects","authors":"R. Grasso, J.E. Ackleson, C. G. Stimson, C. M. Vann, J. W. Buckle, C.P. Pratty, J. A. Haigh, W.R. Pommeroy, S. Price, M. Roberts","doi":"10.1109/CLEOE.2000.909695","DOIUrl":"https://doi.org/10.1109/CLEOE.2000.909695","url":null,"abstract":"Summary form only given. Northrop Grumman (US) and Defense Evaluation and Research Agency (DERA) (UK) report upon a program to characterize the performance of its (OASYS) Obstacle Avoidance Imaging Laser Radar System against various terrestrial targets. High resolution laser radar images of various naturally occurring and manmade terrestrial objects were obtained and their properties measured. These objects include 1) wires of various diameter and reflectivity, 2) trees and vegetation, 3) large and small vertical objects including transmission towers and poles, 4) buildings and structures, and 5) various terrain types. OASYS can discriminate and identify objects against a complementary background. This allows realization of objects that cannot otherwise be seen using other active and passive detection systems.","PeriodicalId":250878,"journal":{"name":"Conference Digest. 2000 Conference on Lasers and Electro-Optics Europe (Cat. No.00TH8505)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129115865","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 : 2000-09-10DOI: 10.1109/CLEOE.2000.910044
M. Sakai, T. Kozeki, H. Ohtake, N. Sarukura, Zhenlin Liu, K. Shimamura, K. Nakano, N. Mujilatu, T. Fukuda
Summary form only given. Ce/sup 3+/:LiCaAlF/sub 4/ (Ce:LiCAF) is already known as practical tunable ultraviolet laser crystal pumped with the fourth harmonic of an Nd:YAG laser. 60 mJ output from this laser medium was already demonstrated with large-sized CZ-grown crystal. If other pumping schemes were available, it would expand the applicability of this laser medium. In this paper, we report on the observation of new excitation channel of Ce/sup 3+/ through LiCAF host crystal.
{"title":"Observation of new excitation channel of cerium ion through LiCAF host crystal","authors":"M. Sakai, T. Kozeki, H. Ohtake, N. Sarukura, Zhenlin Liu, K. Shimamura, K. Nakano, N. Mujilatu, T. Fukuda","doi":"10.1109/CLEOE.2000.910044","DOIUrl":"https://doi.org/10.1109/CLEOE.2000.910044","url":null,"abstract":"Summary form only given. Ce/sup 3+/:LiCaAlF/sub 4/ (Ce:LiCAF) is already known as practical tunable ultraviolet laser crystal pumped with the fourth harmonic of an Nd:YAG laser. 60 mJ output from this laser medium was already demonstrated with large-sized CZ-grown crystal. If other pumping schemes were available, it would expand the applicability of this laser medium. In this paper, we report on the observation of new excitation channel of Ce/sup 3+/ through LiCAF host crystal.","PeriodicalId":250878,"journal":{"name":"Conference Digest. 2000 Conference on Lasers and Electro-Optics Europe (Cat. No.00TH8505)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130578954","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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