In this paper, we present simulation results of an electrooptical variable optical attenuator (VOA) integrated in silicon-on-insulator waveguide. The device is functionally based on free carriers absorption to achieve...In this paper, we present simulation results of an electrooptical variable optical attenuator (VOA) integrated in silicon-on-insulator waveguide. The device is functionally based on free carriers absorption to achieve attenuation. Beam propagation method (BPM) and two-dimensional semiconductor device simulation tool PISCES-II were used to analyze the dc and transient characteristics of the device. The device has a response time (including rise time and fall time) less than 200 ns, much faster than the thermooptic and micro-electromechanical systems (MEMSs) based VOAs.展开更多
Optical parametric lasers widely using in many science and technology field owin g to its merit of wide tunable spectrum range.But common optical parametric lase rs achieve tune by change of angel or temperature.The t...Optical parametric lasers widely using in many science and technology field owin g to its merit of wide tunable spectrum range.But common optical parametric lase rs achieve tune by change of angel or temperature.The tune velocity and tune pre cision of these tune modes does not satisfy in many applications.The reporting i nto an optical parametric laser which achieve tune by electooptic effect,that have got speediness tune velocity and relatively quite tune precision. The optical parametric device design based on parametric fluorescent produce thr ough sum frequency phase matching in nonlinear optical crystals.It is a tune pr o cess of refractive index about parametric and pump light in nonlinear optical cr ystals namely.But refractive index of nonlinear optical crystals possess electro o ptic effect can change via apply transformable electro field.This change only w a nts a time of ns grade.So optical parametric device with nonlinear optical cryst als possess suitability electrooptic effect can realize speediness tune in princ iple.The idea about design on the recommended device here is somewhat as follows .The tune model is phase tuning.To strive increase the effect of electro optic f unction under keep immovable polarization directions of 3 wavelength in the opti cal parametric process,to strive convenient for apply electro field,the electro field is only sensitive for a refractive index of some wavelength in specificall y spectrum region.The principium examination has showed that the idea is reasona ble.Our count have show also that its tune precision same as expectance.展开更多
In terms of the coupled mode theory, microring resonance and electro-optic modulation princeple, a reasonable project is proposed for designing an electro-optic switch with the series-coupled multiple microring resona...In terms of the coupled mode theory, microring resonance and electro-optic modulation princeple, a reasonable project is proposed for designing an electro-optic switch with the series-coupled multiple microring resonators. The simulation and optimization are performed at the resonant wavelength of 1550 nm. The results are as follows: the core size of the microring is 1.6 μm×1.6 μm, the confined layer between the core and the electrode is 1.6 μm, the thickness of the electrode is 0.15 μm, the radius of the m...展开更多
In order to decrease dispersion penalty and increase the optical bandwidth efficiency,an optical single-side-band modulation(SSBM) scheme in sub-carrier multiplexing(SCM) is proposed.The principle of the SSBM is analy...In order to decrease dispersion penalty and increase the optical bandwidth efficiency,an optical single-side-band modulation(SSBM) scheme in sub-carrier multiplexing(SCM) is proposed.The principle of the SSBM is analytically presented,and a configuration for generating optical SSB signal is proposed using a balanced Mach-Zehnder electro-optic modulator.展开更多
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 band characteristics of two-dimensional(2D) lead lanthanum zirconate titanate(PLZT) photonic crystals are analyzed by finite element method.The electro-optic effect of PLZT can cause the refractive index change wh...The band characteristics of two-dimensional(2D) lead lanthanum zirconate titanate(PLZT) photonic crystals are analyzed by finite element method.The electro-optic effect of PLZT can cause the refractive index change when it is imposed by the applied electric field,and the band structure of 2D photonic crystals based on PLZT varies accordingly.The effect of the applied electric field on the structural characteristics of the first and second band gaps in 2D PLZT photonic crystals is analyzed in detail.And the results show that for each band gap,the variations of start wavelength,cut-off wavelength and bandwidth are proportional to quadratic of the electric field.展开更多
A non-linear optical（NLO） material was synthesized by means of a simple method.This material can be applied in electro-optical（EO） devices,such as EO switches and modulators.The Disperse Red 1（DR1） was doped in ...A non-linear optical（NLO） material was synthesized by means of a simple method.This material can be applied in electro-optical（EO） devices,such as EO switches and modulators.The Disperse Red 1（DR1） was doped in polymethyl-methacrylate-co-glycidyl methacrylate（PMMA-co-GMA） as the NLO active chromophore.The synthesis process and material structure were expressed.The thermal properties,surface morphology and optical characteristics of the material were investigated by means of differential scanning calorimetry（DSC）,thermogravimetric analysis（TGA）,atomic force microscopy（AFM）,and m-lines technique.Using the reflection technique,the value of the electro-optical coefficient γ 33 was measured as 11 pm/V at a wavelength of 1310 nm.An EO switch with nanosecond response based on this material has been fabricated.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
In Brillouin distributed optical fiber sensor, using optical coherent detection to detect Brillouin scattering optical signal is a good method, but there exists the polarization correlated detection problem. A novel d...In Brillouin distributed optical fiber sensor, using optical coherent detection to detect Brillouin scattering optical signal is a good method, but there exists the polarization correlated detection problem. A novel detecting scheme is presented and demonstrated experimentally, which adopts orthogonal polarization diversity reception to resolve the polarization correlated detection problem. A laser is used as pump and reference light sources, a microwave electric-optical modulator (EOM) is adopted to produce frequency shift reference light, a polarization controller is used to control the polarization of the reference light which is changed into two orthogonal polarization for two adjacent acquisition periods. The Brillouin scattering light is coherently detected with the reference light, and the Brillouin scattering optical signal is taken out based on Brillouin frequency shift. After electronic processing, better Brillouin distributed sensing signal is obtained. A 25-km Brillouin distributed optical fi展开更多
A diode-end-pumped electro-optic （EO） Q-switched Nd：YVO4 laser operating at repetition rate of 10 kpps （pulses per second） was reported. A block of La3Ga5SiO14 （LGS） single crystal was used as a Q-switch and th...A diode-end-pumped electro-optic （EO） Q-switched Nd：YVO4 laser operating at repetition rate of 10 kpps （pulses per second） was reported. A block of La3Ga5SiO14 （LGS） single crystal was used as a Q-switch and the driver was a metal oxide semiconductor field effect transistor （MOS-FET） pulser of high repetition rate and high voltage. At continuous wave （CW） operation, the slope efficiency of the laser was 46%, and maximum optical-to-optical efficiency was 38.5%. Using an output coupler with transmission of 70%, a 10-kpps Q-switched pulse train with 0.4-mJ monopulse energy and 8.2-ns pulse width was achieved, the optical conversion efficiency was around 15%, and the beam quality M^2 factor was less than 1.2.展开更多
A 100-Gb/s high-speed optical transmitter is proposed and experimentally demonstrated. Based on frequency-quadrupling technique, two sub-channels with a fixed 50-GHz spacing are obtained from one laser source. Using r...A 100-Gb/s high-speed optical transmitter is proposed and experimentally demonstrated. Based on frequency-quadrupling technique, two sub-channels with a fixed 50-GHz spacing are obtained from one laser source. Using return-to-zero differential quadrature phase-shift keying （RZ-DQPSK） modulation format and polarization multiplexing （PolMux）, only low-speed electronic devices of 12.5 GHz are needed for the 100-Gb/s transmitter. This eliminates the need of ultrahigh-speed optoelectronic devices and thus greatly reduces the cost. The experimental results show that this transmitter can achieve good performance in dispersion tolerance of a 25-km single mode fiber （SMF）.展开更多
Electro-optic （EO） effect and thermo-optic （TO） effect are jointly considered on the basis of field-induced and temperature-affected perturbations of the operating point in waveguide components. TO coefficients of...Electro-optic （EO） effect and thermo-optic （TO） effect are jointly considered on the basis of field-induced and temperature-affected perturbations of the operating point in waveguide components. TO coefficients of EO fluorinated polyimide films with side-chain azobenzene chromophore were measured by attenuated- total-reflection （ATR） technique at different temperatures with TE- and TM-polarized lights, respectively. It is found that the absolute values of TO coefficients increase with the increments of both chromophore concentration and film thickness, but the polarization dependence of TO coefficients increases with the increment of chromophore concentration and decreases with the increment of film thickness.展开更多
A high-permittivity （high-k） material is applied as the gate dielectric layer in a silicon metal-oxide- semiconductor （MOS） capacitor to form a special electro-optic （EO） modulator. Both induced charge density a...A high-permittivity （high-k） material is applied as the gate dielectric layer in a silicon metal-oxide- semiconductor （MOS） capacitor to form a special electro-optic （EO） modulator. Both induced charge density and modulation efficiency in the proposed modulator are improved due to the special structure design and the application of the high-k material. The device has an ultra-compact dimension of 691 μm in length.展开更多
A polymer-stabilized blue phase liquid crystal display （BPLCD） with slanted wall-shaped electrodes is proposed. Compared with the traditional BPLCD with wall-shaped electrodes, the electrodes of the proposed BPLCD a...A polymer-stabilized blue phase liquid crystal display （BPLCD） with slanted wall-shaped electrodes is proposed. Compared with the traditional BPLCD with wall-shaped electrodes, the electrodes of the proposed BPLCD are slightly angled to obtain phase retardation in the entire cell even at the position of electrodes. The proposed BPLCD demonstrates a relatively higher average transmittance and overall brightness than the traditional BPLCD.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
A novel 1.55-μm spot-size converter integrated electroabsorption modulator was designed with conventional photolithography and chemical wet etching process. A ridge double-core structure was employed for the modulato...A novel 1.55-μm spot-size converter integrated electroabsorption modulator was designed with conventional photolithography and chemical wet etching process. A ridge double-core structure was employed for the modulator, and a buried ridge double-core structure was incorporated for the spot-size converter. The passive waveguide was optically combined with a laterally tapered active waveguide to control the mode size. The figure of merit is 4.1667 dB/V(/100 μm) and the beam divergence angles in the horizontal and vertical directions were as small as 11.2°and 13.0°, respectively.展开更多
A tunable Fabry-Perot (F-P) filter by using electro-optic polymer film is proposed. The electro-optic polymer is alkoxysilane dye (ASD)/SiO2-TiO2 hybrid material, whose electro-optic coefficient 733 is about 5 pm/V, T...A tunable Fabry-Perot (F-P) filter by using electro-optic polymer film is proposed. The electro-optic polymer is alkoxysilane dye (ASD)/SiO2-TiO2 hybrid material, whose electro-optic coefficient 733 is about 5 pm/V, The wavelength tuning range of 3.8 nm under 400-V DC voltage and the nonlinear characteristic with the electric field have been obtained via electro-optical properties of polymer. Both of polymer film fabrication and F-P filter design have been introduced. The tunable F-P filter is designed for the application of two-input/two-output port wavelength-selective optical switch. Also, some problems have been discussed in this letter.展开更多
基金This work was supported by the National Natural Science Foundation of China under Grant Nos. 69896260 and 69990540, and the "973" Project by the National Science and Technology Ministry under Contract No. G20000366. Q. Yan's e-mail address is qfyan@red.s
文摘In this paper, we present simulation results of an electrooptical variable optical attenuator (VOA) integrated in silicon-on-insulator waveguide. The device is functionally based on free carriers absorption to achieve attenuation. Beam propagation method (BPM) and two-dimensional semiconductor device simulation tool PISCES-II were used to analyze the dc and transient characteristics of the device. The device has a response time (including rise time and fall time) less than 200 ns, much faster than the thermooptic and micro-electromechanical systems (MEMSs) based VOAs.
文摘Optical parametric lasers widely using in many science and technology field owin g to its merit of wide tunable spectrum range.But common optical parametric lase rs achieve tune by change of angel or temperature.The tune velocity and tune pre cision of these tune modes does not satisfy in many applications.The reporting i nto an optical parametric laser which achieve tune by electooptic effect,that have got speediness tune velocity and relatively quite tune precision. The optical parametric device design based on parametric fluorescent produce thr ough sum frequency phase matching in nonlinear optical crystals.It is a tune pr o cess of refractive index about parametric and pump light in nonlinear optical cr ystals namely.But refractive index of nonlinear optical crystals possess electro o ptic effect can change via apply transformable electro field.This change only w a nts a time of ns grade.So optical parametric device with nonlinear optical cryst als possess suitability electrooptic effect can realize speediness tune in princ iple.The idea about design on the recommended device here is somewhat as follows .The tune model is phase tuning.To strive increase the effect of electro optic f unction under keep immovable polarization directions of 3 wavelength in the opti cal parametric process,to strive convenient for apply electro field,the electro field is only sensitive for a refractive index of some wavelength in specificall y spectrum region.The principium examination has showed that the idea is reasona ble.Our count have show also that its tune precision same as expectance.
基金supported by the National Natural ScienceFoundation of China (60706011)the National "973" Project ofChina(2006CB302803)+1 种基金the Fund of Chinese Ministry of Educa-tion (20070183087)the Fund of Science and Technology ofJilin Province of China(20080125).
文摘In terms of the coupled mode theory, microring resonance and electro-optic modulation princeple, a reasonable project is proposed for designing an electro-optic switch with the series-coupled multiple microring resonators. The simulation and optimization are performed at the resonant wavelength of 1550 nm. The results are as follows: the core size of the microring is 1.6 μm×1.6 μm, the confined layer between the core and the electrode is 1.6 μm, the thickness of the electrode is 0.15 μm, the radius of the m...
基金supported by Science Foundation for Youthful Teachers of Anhui University (Grant No.2007jql104)
文摘In order to decrease dispersion penalty and increase the optical bandwidth efficiency,an optical single-side-band modulation(SSBM) scheme in sub-carrier multiplexing(SCM) is proposed.The principle of the SSBM is analytically presented,and a configuration for generating optical SSB signal is proposed using a balanced Mach-Zehnder electro-optic modulator.
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.
基金supported by the National Natural Science Foundation of China (No.6087047) the Doctoral Fund of Ministry of Education of China (No.20070216004)
文摘The band characteristics of two-dimensional(2D) lead lanthanum zirconate titanate(PLZT) photonic crystals are analyzed by finite element method.The electro-optic effect of PLZT can cause the refractive index change when it is imposed by the applied electric field,and the band structure of 2D photonic crystals based on PLZT varies accordingly.The effect of the applied electric field on the structural characteristics of the first and second band gaps in 2D PLZT photonic crystals is analyzed in detail.And the results show that for each band gap,the variations of start wavelength,cut-off wavelength and bandwidth are proportional to quadratic of the electric field.
基金Supported by the National Natural Science Foundation of China(Nos.61107019,61177027,61077041,60807029)the Science Foundation for Young Scientists of Jilin Province,China(No. 20100174)+1 种基金the Science and Technology Development Plan of Jilin Province,China(No.20110315)the Program for Special Funds of Basic Science & Technology of Jilin University,China(Nos.201103071,201100253,200905005)
文摘A non-linear optical（NLO） material was synthesized by means of a simple method.This material can be applied in electro-optical（EO） devices,such as EO switches and modulators.The Disperse Red 1（DR1） was doped in polymethyl-methacrylate-co-glycidyl methacrylate（PMMA-co-GMA） as the NLO active chromophore.The synthesis process and material structure were expressed.The thermal properties,surface morphology and optical characteristics of the material were investigated by means of differential scanning calorimetry（DSC）,thermogravimetric analysis（TGA）,atomic force microscopy（AFM）,and m-lines technique.Using the reflection technique,the value of the electro-optical coefficient γ 33 was measured as 11 pm/V at a wavelength of 1310 nm.An EO switch with nanosecond response based on this material has been fabricated.
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.
基金This work was supported by the Zhejiang Provincial Natural Science Foundation of China under Grant No. 603127.
文摘In Brillouin distributed optical fiber sensor, using optical coherent detection to detect Brillouin scattering optical signal is a good method, but there exists the polarization correlated detection problem. A novel detecting scheme is presented and demonstrated experimentally, which adopts orthogonal polarization diversity reception to resolve the polarization correlated detection problem. A laser is used as pump and reference light sources, a microwave electric-optical modulator (EOM) is adopted to produce frequency shift reference light, a polarization controller is used to control the polarization of the reference light which is changed into two orthogonal polarization for two adjacent acquisition periods. The Brillouin scattering light is coherently detected with the reference light, and the Brillouin scattering optical signal is taken out based on Brillouin frequency shift. After electronic processing, better Brillouin distributed sensing signal is obtained. A 25-km Brillouin distributed optical fi
文摘A diode-end-pumped electro-optic （EO） Q-switched Nd：YVO4 laser operating at repetition rate of 10 kpps （pulses per second） was reported. A block of La3Ga5SiO14 （LGS） single crystal was used as a Q-switch and the driver was a metal oxide semiconductor field effect transistor （MOS-FET） pulser of high repetition rate and high voltage. At continuous wave （CW） operation, the slope efficiency of the laser was 46%, and maximum optical-to-optical efficiency was 38.5%. Using an output coupler with transmission of 70%, a 10-kpps Q-switched pulse train with 0.4-mJ monopulse energy and 8.2-ns pulse width was achieved, the optical conversion efficiency was around 15%, and the beam quality M^2 factor was less than 1.2.
基金the"863"Program of China under Grant No.2006AA01Z255.
文摘A 100-Gb/s high-speed optical transmitter is proposed and experimentally demonstrated. Based on frequency-quadrupling technique, two sub-channels with a fixed 50-GHz spacing are obtained from one laser source. Using return-to-zero differential quadrature phase-shift keying （RZ-DQPSK） modulation format and polarization multiplexing （PolMux）, only low-speed electronic devices of 12.5 GHz are needed for the 100-Gb/s transmitter. This eliminates the need of ultrahigh-speed optoelectronic devices and thus greatly reduces the cost. The experimental results show that this transmitter can achieve good performance in dispersion tolerance of a 25-km single mode fiber （SMF）.
文摘Electro-optic （EO） effect and thermo-optic （TO） effect are jointly considered on the basis of field-induced and temperature-affected perturbations of the operating point in waveguide components. TO coefficients of EO fluorinated polyimide films with side-chain azobenzene chromophore were measured by attenuated- total-reflection （ATR） technique at different temperatures with TE- and TM-polarized lights, respectively. It is found that the absolute values of TO coefficients increase with the increments of both chromophore concentration and film thickness, but the polarization dependence of TO coefficients increases with the increment of chromophore concentration and decreases with the increment of film thickness.
文摘A high-permittivity （high-k） material is applied as the gate dielectric layer in a silicon metal-oxide- semiconductor （MOS） capacitor to form a special electro-optic （EO） modulator. Both induced charge density and modulation efficiency in the proposed modulator are improved due to the special structure design and the application of the high-k material. The device has an ultra-compact dimension of 691 μm in length.
基金supported by the National Natural Science Foundation of China under Nos. 60877004 and 61036008
文摘A polymer-stabilized blue phase liquid crystal display （BPLCD） with slanted wall-shaped electrodes is proposed. Compared with the traditional BPLCD with wall-shaped electrodes, the electrodes of the proposed BPLCD are slightly angled to obtain phase retardation in the entire cell even at the position of electrodes. The proposed BPLCD demonstrates a relatively higher average transmittance and overall brightness than the traditional BPLCD.
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.
文摘A novel 1.55-μm spot-size converter integrated electroabsorption modulator was designed with conventional photolithography and chemical wet etching process. A ridge double-core structure was employed for the modulator, and a buried ridge double-core structure was incorporated for the spot-size converter. The passive waveguide was optically combined with a laterally tapered active waveguide to control the mode size. The figure of merit is 4.1667 dB/V(/100 μm) and the beam divergence angles in the horizontal and vertical directions were as small as 11.2°and 13.0°, respectively.
文摘A tunable Fabry-Perot (F-P) filter by using electro-optic polymer film is proposed. The electro-optic polymer is alkoxysilane dye (ASD)/SiO2-TiO2 hybrid material, whose electro-optic coefficient 733 is about 5 pm/V, The wavelength tuning range of 3.8 nm under 400-V DC voltage and the nonlinear characteristic with the electric field have been obtained via electro-optical properties of polymer. Both of polymer film fabrication and F-P filter design have been introduced. The tunable F-P filter is designed for the application of two-input/two-output port wavelength-selective optical switch. Also, some problems have been discussed in this letter.
