Ultrafast optoelectronic technology has been widely used in terahertz time domain spectrum,terahertz imaging technology,terahertz communication and so on,and great progress has been achieved in the past two decade.Rec...Ultrafast optoelectronic technology has been widely used in terahertz time domain spectrum,terahertz imaging technology,terahertz communication and so on,and great progress has been achieved in the past two decade.Recently,this innovative technology has been applied in radio metrology and supplied a potential and hopeful method to solve the existent challenges of calibration devices and equipments with bandwidth up to 100 GHz.This paper generally summarizes the emerging applications of the ultrafast optoelectronic technology in radio metrology.The main applications of this technology in calibrating broadband sampling oscilloscopes,the high-speed photodiodes and calibrating the electrical pulse generators are emphasized,and the testing of monolithic microwave integrated circuits is also presented.展开更多
An eighth-order Landau–Devonshire theory is constructed to investigate the piezoelectric and electro–optic properties of tetragonal（1- x）Pb（Mg1/3Nb2/3）O3–xPbTiO3 single crystals（x = 0.38 and x = 0.4）. The die...An eighth-order Landau–Devonshire theory is constructed to investigate the piezoelectric and electro–optic properties of tetragonal（1- x）Pb（Mg1/3Nb2/3）O3–xPbTiO3 single crystals（x = 0.38 and x = 0.4）. The dielectric stiffness coefficients of the Landau potential are obtained by fitting to the dielectric properties and the phase transition temperature between cubic phase and tetragonal phase. It is indicated that tetragonal（1- x）Pb（Mg1/3Nb2/3）O3–xPbTiO3 single crystals have the firstorder cubic-tetragonal phase transitions. The dielectric constants are in great agreement with the experimental results.The piezoelectric coefficients d33 and d31at room temperature are about 145 p C/N and-62 p C/N respectively which are smaller than that of（1- x）Pb（Mg1/3Nb2/3）O3–xPbTiO3 single crystals around the morphotropic phase boundary.Moreover, tetragonal（1- x）Pb（Mg1/3Nb2/3）O3–xPbTiO3 single crystals have the linear electro–optic coefficients rc =33.7 pm/V and rc = 28.8 pm/V for x = 0.38 and x = 0.4, respectively which are in accordance with the measurements.展开更多
A novel optical analog-to-digital converter based on optical time division multiplexing(OTDM) is described which uses electrooptic sampling and time-demultiplexing together with multiple electronic analog-to-digital c...A novel optical analog-to-digital converter based on optical time division multiplexing(OTDM) is described which uses electrooptic sampling and time-demultiplexing together with multiple electronic analog-to-digital converter(ADC). Compared with the previous scheme, the time-division multiplexer and the time-division demultiplexer are applied in the optical analog-to-digital converter(OADC) at the same time, the design of the OADC is simplified and the performance of the OADC based on time-division demultiplexer is improved. A core optical part of the system is demonstrated with a sample rate of 10 Gs/s. The signals in three channels are demultiplexed from the optical pulses.The result proves our scheme is feasible.展开更多
The transparent solid medium of a thermotropic liquid crystal polymer have a comb structure of mesogenic side chains which exhibit a nonlinear optical response of electronic origin.The main chain of the liquid crystal...The transparent solid medium of a thermotropic liquid crystal polymer have a comb structure of mesogenic side chains which exhibit a nonlinear optical response of electronic origin.The main chain of the liquid crystal polymers can be selected from a number of suitable polymerized monomeric and comonomeric structures such as polyvinyl,polysiloxane,polyoxyalkylene, polyester etc.The electrooptic light modulator is provided,which have potential to using in the systems of laser modulation and deflection,and information control in optical circuitry etc.展开更多
We describe a fiber optic hydrophone array system that could be used for underwater acoustic surveillance applications （e.g. military, counter terrorist, and customs authorities in protecting ports and harbors）, off...We describe a fiber optic hydrophone array system that could be used for underwater acoustic surveillance applications （e.g. military, counter terrorist, and customs authorities in protecting ports and harbors）, offshore production facilities or coastal approaches as well as various marine applications. In this paper, we propose a new approach to underwater sonar systems using the voltage-controlled liquid crystals and simple multiplexing method. The proposed method permits measurement of sound under water at multiple points along an optical fiber using the low cost components and standard single mode fiber, without complex interferometric measurement techniques, electronics or demodulation software.展开更多
文摘Ultrafast optoelectronic technology has been widely used in terahertz time domain spectrum,terahertz imaging technology,terahertz communication and so on,and great progress has been achieved in the past two decade.Recently,this innovative technology has been applied in radio metrology and supplied a potential and hopeful method to solve the existent challenges of calibration devices and equipments with bandwidth up to 100 GHz.This paper generally summarizes the emerging applications of the ultrafast optoelectronic technology in radio metrology.The main applications of this technology in calibrating broadband sampling oscilloscopes,the high-speed photodiodes and calibrating the electrical pulse generators are emphasized,and the testing of monolithic microwave integrated circuits is also presented.
基金Project supported by the National Natural Science Foundation of China(Grant No.51335002)the Changzhou Science and Technology Project,China(Grant No.CJ20130022)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘An eighth-order Landau–Devonshire theory is constructed to investigate the piezoelectric and electro–optic properties of tetragonal（1- x）Pb（Mg1/3Nb2/3）O3–xPbTiO3 single crystals（x = 0.38 and x = 0.4）. The dielectric stiffness coefficients of the Landau potential are obtained by fitting to the dielectric properties and the phase transition temperature between cubic phase and tetragonal phase. It is indicated that tetragonal（1- x）Pb（Mg1/3Nb2/3）O3–xPbTiO3 single crystals have the firstorder cubic-tetragonal phase transitions. The dielectric constants are in great agreement with the experimental results.The piezoelectric coefficients d33 and d31at room temperature are about 145 p C/N and-62 p C/N respectively which are smaller than that of（1- x）Pb（Mg1/3Nb2/3）O3–xPbTiO3 single crystals around the morphotropic phase boundary.Moreover, tetragonal（1- x）Pb（Mg1/3Nb2/3）O3–xPbTiO3 single crystals have the linear electro–optic coefficients rc =33.7 pm/V and rc = 28.8 pm/V for x = 0.38 and x = 0.4, respectively which are in accordance with the measurements.
文摘A novel optical analog-to-digital converter based on optical time division multiplexing(OTDM) is described which uses electrooptic sampling and time-demultiplexing together with multiple electronic analog-to-digital converter(ADC). Compared with the previous scheme, the time-division multiplexer and the time-division demultiplexer are applied in the optical analog-to-digital converter(OADC) at the same time, the design of the OADC is simplified and the performance of the OADC based on time-division demultiplexer is improved. A core optical part of the system is demonstrated with a sample rate of 10 Gs/s. The signals in three channels are demultiplexed from the optical pulses.The result proves our scheme is feasible.
文摘The transparent solid medium of a thermotropic liquid crystal polymer have a comb structure of mesogenic side chains which exhibit a nonlinear optical response of electronic origin.The main chain of the liquid crystal polymers can be selected from a number of suitable polymerized monomeric and comonomeric structures such as polyvinyl,polysiloxane,polyoxyalkylene, polyester etc.The electrooptic light modulator is provided,which have potential to using in the systems of laser modulation and deflection,and information control in optical circuitry etc.
文摘We describe a fiber optic hydrophone array system that could be used for underwater acoustic surveillance applications （e.g. military, counter terrorist, and customs authorities in protecting ports and harbors）, offshore production facilities or coastal approaches as well as various marine applications. In this paper, we propose a new approach to underwater sonar systems using the voltage-controlled liquid crystals and simple multiplexing method. The proposed method permits measurement of sound under water at multiple points along an optical fiber using the low cost components and standard single mode fiber, without complex interferometric measurement techniques, electronics or demodulation software.
