Journals >Chinese Journal of Quantum Electronics
Contents
2006
Volume: 23 Issue 6
26 Article(s)
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Research Article
Measurement of laser frequencies with femlosecond mode-locked lasers
Bin-quan ZHOU, and Fu-li LI
The work of the winners of the 2005 Nobel prize in physics is briefly reviewed. They measured the frequency of light with mode-locked laser comb. Femtosecond laser-frequency comb techniques are vastly simplifying the measurement. A single mode-locked femtosecond laser,its spectrum broadened by self-phase modulation in The work of the winners of the 2005 Nobel prize in physics is briefly reviewed. They measured the frequency of light with mode-locked laser comb. Femtosecond laser-frequency comb techniques are vastly simplifying the measurement. A single mode-locked femtosecond laser,its spectrum broadened by self-phase modulation in a photonic crystal fiber,can produce millions of sharp laser lines in a precise evenly spaced grid spanning much of the visible and near-infrared spectrum,the spacing of the frequency equal to the repetition of the modelocked pulse. They measured the radio frequency instead of optical frequency measurement with optical frequency comb and technology of octave-spanning. This is a significant step toward precision of optical frequency measurement and precision of atomic clock and a new brilliancy in physics and metrology..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 753 (2006)
New progress of exciton condensation in coupled quantum wells
Zhan-biao YAN, and Zhen-ning GUO
The possible way offered by Bose-Einstein condensation for investigating the quantum world made much progress for exciton condensation in semiconductor nanometer structures. In particular,the lifetime of indirect excitons has been dramatically improved by more than two orders of magnitudes by using the spatial separatiThe possible way offered by Bose-Einstein condensation for investigating the quantum world made much progress for exciton condensation in semiconductor nanometer structures. In particular,the lifetime of indirect excitons has been dramatically improved by more than two orders of magnitudes by using the spatial separation of electrons and holes that form excitons in coupled quantum wells. This allows the excitons to be cooled down below 1 K and the condensation or highly degenerate states of excitons to be realized experimentally.Phenomena in the cold exciton gases such as condensation,pattern formation and macroscopically ordered exciton states were reviewed. Understanding the formation mechanisms of these degenerate exciton systems can open new opportunities for the last realization of exciton Bose-Einstein condensation in semiconductor nanometer structures..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 759 (2006)
Recent progress of single-photon sources and single-photon detectors
Jian-jun LI, Xiao-bing ZHENG, and Yu FENG
Among the various implementations of quantum information,optical methods are unique as they allow long distance communication and provide new ways to quantum computation. Important elements used in optical quantum information processing are single photon detectors and sources. Methods for producing and measuring singleAmong the various implementations of quantum information,optical methods are unique as they allow long distance communication and provide new ways to quantum computation. Important elements used in optical quantum information processing are single photon detectors and sources. Methods for producing and measuring single photons were reviewed and their applicationes in quantum information processing were discussed..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 766 (2006)
Analysis on the space-based optic observation mode for space object
Jian-hui YU, Zeng-li SU, and Qian TAN
Space surveillance usually adopts ground-based and space-based means. Compared to ground-based observation,space-based observation has advantages in coverage of space and in time. Space-based observation technology for space object becomes most important technology in the field of space. Now many countries and organizaSpace surveillance usually adopts ground-based and space-based means. Compared to ground-based observation,space-based observation has advantages in coverage of space and in time. Space-based observation technology for space object becomes most important technology in the field of space. Now many countries and organizations have energetically developed space-based observation technology. The space-based optic observation applies optic fence,specifying space area and geosychronous orbit means for searching,star-tracking means for orienting,waiting or tracking means for imaging..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 772 (2006)
Nonparaxial vectorial off-axis elliptical Gaussian beam diffraction at a rectangular aperture
Wen-yu FU
On the basis of vector Rayleigh diffraction integral formula,an analytical expression for the diffraction of nonparaxial vectorial off-axis elliptical Gaussian beam at a rectangular aperture is derived. And according to that,the on-off and far-field expressions for rectangular diffraction,the propagation formula in freOn the basis of vector Rayleigh diffraction integral formula,an analytical expression for the diffraction of nonparaxial vectorial off-axis elliptical Gaussian beam at a rectangular aperture is derived. And according to that,the on-off and far-field expressions for rectangular diffraction,the propagation formula in free space,slit diffraction and the paraxial far-field diffraction formulae are obtained. It is shown that the f parameter,truncation parameter and relative off-axis parameter affect together the beam nonparaxiality..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 777 (2006)
Discussion and analysis of Schmidt system
Pei-ming HAO, Bao-zhu PAN, Hong-guang LI, and Wei-wei LI
It is well known that Schmidt system is a famous optical system. The equation of the corrector plate which was based on the third-order aberration theory was approved for a long time. When we confirmed the previous equation with optical design program ZEMAX,we found the coefficient of the equation a≠1/2r02,where r02 waIt is well known that Schmidt system is a famous optical system. The equation of the corrector plate which was based on the third-order aberration theory was approved for a long time. When we confirmed the previous equation with optical design program ZEMAX,we found the coefficient of the equation a≠1/2r02,where r02 was the radius of the corrector plate vertex,and ΣS1≠0,the focal length f and the back focal length fb of Schmidt system also had some deviation,and didn't coincide with the third-order aberration theory. According to analysis,the cause of the errors was that the previous equation didn't contain the variation of the focal length after defocus Δ. The focal length after defocus should be f△=f+△.From the third-order aberration theory,substituting f with fΔ in calculation,we got a new equation of the corrector plate. Again,when we confirmed the new equation with optical design program ZEMAX,we could deduce that the coefficient a=1/2r02,andΣS1=0,which accorded with third-order aberration theory..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 783 (2006)
Design and manufacture of Hartmann beam expander with wide aperture
Pei-ming HAO, Wei-wei LI, Hong-guang LI, Bao-zhu PAN, and Sen-lin ZHOU
The manufacture of transmission optics beam expander used in Hartmann wavefront detection system was introduced. Based on the third-order aberration theory,the reasons why off-axis aberrations can't be well corrected for traditional beam expander were analyzed.Submitting the primary parameters to optical design sofThe manufacture of transmission optics beam expander used in Hartmann wavefront detection system was introduced. Based on the third-order aberration theory,the reasons why off-axis aberrations can't be well corrected for traditional beam expander were analyzed.Submitting the primary parameters to optical design software of ZEMAX,a new type of beam expander which can perfectly correct the on-axis and off-axis aberrations is designed.It provided with wide aperture,large relative aperture and large field of vision. According to the actual demands of Hartmann beam expander,a concrete design example is presented,and corresponding mechanical design is matched for it. The ways of fabrication,adjusting and testing are introduced too..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 788 (2006)
Cascaded systems for optical image encryption based on diffractive optical elements
Guo-hai SITU, Jing-juan ZHANG, and Yi-shi SHI
Cascaded systems for optical image encryption based on diffractive optical elements are presented. Generally,a cascaded system with n-stages is a 2n-f system constituted with n lens aligning in serial. N diffractive optical elements(DOES)such as phase masks are located in the spatial and the frequency domains of the syCascaded systems for optical image encryption based on diffractive optical elements are presented. Generally,a cascaded system with n-stages is a 2n-f system constituted with n lens aligning in serial. N diffractive optical elements(DOES)such as phase masks are located in the spatial and the frequency domains of the system so as to decrypt the primary image at the output when the system is illuminated with a corresponding plane wave. These DOEs are designed with the cascaded iterative Fourier transform(CIFT)algorithm. Computer simulations indicate that such algorithms converge very fast,and that the larger the stages number,the faster the convergent speed for the corresponding algorithm. The cascaded systems can perform high quality decryption. Numerical results show that the mean square error between the decrypted image and the primary image can be less than 5×10－30. Furthermore,the proposed systems can be used as key-sharing implementation in a multiple users system,and higher security is thus achieved..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 794 (2006)
A new error-correcting method for phase-unwrapping
Wei WANG, Yu XIE, and Bo WU
Many factors,such as noise,speckles and low modulation in wrapped phase make the unwrapping procedure complicated and path-dependent. The traditional scanning algorithm will propagate errors along the predefined path to the boundary. Based on the scanning algorithm,a new error-correcting method,which is combined with fMany factors,such as noise,speckles and low modulation in wrapped phase make the unwrapping procedure complicated and path-dependent. The traditional scanning algorithm will propagate errors along the predefined path to the boundary. Based on the scanning algorithm,a new error-correcting method,which is combined with filtering,is proposed. This method can simply eliminate the propagation of errors after phase unwrapping without avoiding error areas. Also,the results of the simulation and experiment prove its effectiveness..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 798 (2006)
Photodissociation spectra of the complex Mg+-S2(CH3)2
Hua WU, Yi-hua HU, Jia-yong LIN, Ren CHEN, and Li CHEN
Photodissociation spectra of the complex Mg+-S2(CH3)2 in the spectral region of 230～440 nm was observed. Mass spectrometry of the products for photo-induced reaction in the complex Mg+-S2(CH3)2 exhibits the product Mg+ from nonreaction quenching and reactive products Mg+-SCH3 throughout the whole wavelength range. The Photodissociation spectra of the complex Mg+-S2(CH3)2 in the spectral region of 230～440 nm was observed. Mass spectrometry of the products for photo-induced reaction in the complex Mg+-S2(CH3)2 exhibits the product Mg+ from nonreaction quenching and reactive products Mg+-SCH3 throughout the whole wavelength range. The reactive products originate from the rupture of S-S chemical bonds. The photo dissociation spectrum consists of two broad peaks corresponding to the atomic transition of Mg+(32P←32S). The absorption spectrum by CIS method of quantum chemistry calculation agrees with the experimental spectrum..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 802 (2006)
Dual eigenveetors of the Susskind-Glogower phase operators for a two-mode field
Xue-fen XU
We find that there exist dual eigenvectors |■,q>* of the phase state-vectors|■,q> of the two-mode Susskind-Glogower phase operator ei?. By contour integration we show that |■,q>* is the common eigenvector of e－i? and the photon number difference operator. The properties of |■,q>* are studied,it turns out thWe find that there exist dual eigenvectors |■,q>* of the phase state-vectors|■,q> of the two-mode Susskind-Glogower phase operator ei?. By contour integration we show that |■,q>* is the common eigenvector of e－i? and the photon number difference operator. The properties of |■,q>* are studied,it turns out that |■,q>*and|■,q> can compose a completeness relation in contour integration form. A phase state representation for two-mode field is thus presented..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 806 (2006)
Simulation of the multi-qubit quantum Fourier transform
Wei-ying QIAN, and Li SUN
The quantum Fourier transform(QFT)is a key subroutine of many quantum algorithms. NMR technology has been considered as one of the most effective physical system to realize quantum computation. QFT was introduced and drawn. After a further analysis,the quantum network which performs a multi-qubit QFT has been drawn outThe quantum Fourier transform(QFT)is a key subroutine of many quantum algorithms. NMR technology has been considered as one of the most effective physical system to realize quantum computation. QFT was introduced and drawn. After a further analysis,the quantum network which performs a multi-qubit QFT has been drawn out. Relevant unitary transforms of QFT were decomposed according to multiple-quantum operator algebra theory,and we designed the NMR pulse sequences to implement QFT. Finally,multi-qubit QFT was experimentally finished on a quantum computer emulator,which means the work we proposed is reasonable and practical..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 811 (2006)
Teleportation of the three-particle entangled state by two EPR pairs
Xin JI, and Shou ZHANG
A scheme for teleporting a three-particle entangled state is proposed. In the scheme,two EPR pairs are chosen as quantum channels which shared by the sender and the receiver. By introducing an additional qubit and performing CNOT operation as well as appropriate unitary transformation,the three-particle entangled stateA scheme for teleporting a three-particle entangled state is proposed. In the scheme,two EPR pairs are chosen as quantum channels which shared by the sender and the receiver. By introducing an additional qubit and performing CNOT operation as well as appropriate unitary transformation,the three-particle entangled state can be teleported probabilistically..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 816 (2006)
Probabilistic teleportation of an N-particle arbitrary and unknown state via W states
Xiao-ming XIU, Ya-jun GAO, and Li DONG
A representation of an N-particle arbitrary and unknown state is proposed. As an application,a scheme for teleporting an N-particle unknown state via the product state of W states is investigated. The teleportation scheme of an N-particle unknown state can be realized by Alice's Bell-state measurements and Bob'A representation of an N-particle arbitrary and unknown state is proposed. As an application,a scheme for teleporting an N-particle unknown state via the product state of W states is investigated. The teleportation scheme of an N-particle unknown state can be realized by Alice's Bell-state measurements and Bob's computation basis measurements and unitary transformations with the probability of the successful teleportation(2/3)N..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 820 (2006)
Time-evolution of the atom's occupancy of two-mode field interacting with two atoms in Bell states via multiphoton process
Cheng-qiang ZHANG, Xia TAN, and Yun-jie XIA
We investigate the time-evolution of the atom's occupancy in the system of twomode coherent fields interacting with two atoms in Bell states via multiphoton process. The results show that the atom's occupancy is zero if the two atoms are initially in Bell state ■(|+,－>－|－,+>). The atom's occupancy is We investigate the time-evolution of the atom's occupancy in the system of twomode coherent fields interacting with two atoms in Bell states via multiphoton process. The results show that the atom's occupancy is zero if the two atoms are initially in Bell state ■(|+,－>－|－,+>). The atom's occupancy is influenced by three factors,which are the intensity of two dipole-dipole coupled atoms,the coupling constant of light and atoms and the absorbing or emitting photon number per atomic transition,if the two atoms are initially in the other three Bell states. The oscillation frequency of the atom's occupancy accelerates apparently with the increase of the intensity of two dipole-dipole coupled atoms or the absorbing or emitting photon number per atomic transition. The collapse-revival phenomenon of the atom's occupancy disappears when the intensity of two dipole-dipole coupled atoms is increased to some point..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 825 (2006)
Quantum properties of atoms in Tavis-Cummings model with Gaussian coupling
Zhong-chun WANG
The quantum properties of atoms in double-atom Tavis-Cummings model with Gaussian atom-field coupling are studied. The influence of atomic motion perpendicularity to the axes of resonant cavity and initial states of the system on the atomic population inversion and double-atom dipole squeezing are analysed numerically.The quantum properties of atoms in double-atom Tavis-Cummings model with Gaussian atom-field coupling are studied. The influence of atomic motion perpendicularity to the axes of resonant cavity and initial states of the system on the atomic population inversion and double-atom dipole squeezing are analysed numerically. We find that the motion affects the collapse and revival of the atomic inversion,but it doesn't affect the maximun dipole squeezing. The maximun dipole squeezing can be got when the field is vacuum and the atoms are in some special entangled state at the begining..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 830 (2006)
Dipole squeezing in the system of the two-mode entangled coherent field interacting with atoms in Bell states
Ji-cheng LIN, Xiao-hu ZHENG, and Zhuo-liang CAO
The atomic dipole squeezing effects in the system of two identical two-level atoms in the Bell state interacting with the two-mode entangled coherent states field are investigated by means of Schr?dinger equation solution and numerical calculations. The effects of the atomic initial state,mean photon numbers of field,tThe atomic dipole squeezing effects in the system of two identical two-level atoms in the Bell state interacting with the two-mode entangled coherent states field are investigated by means of Schr?dinger equation solution and numerical calculations. The effects of the atomic initial state,mean photon numbers of field,the degree of the entanglment for the entangled coherent fields,and the coupling strength of dipole-dipole interaction between atoms on the atomic dipole squeezing effects are discussed. The results show that dipole squeezing effect does not appear for the Bell state β|00>,|β|01> and|β11>,however there can appear the dipole squeezing effects under some conditions for the Bell state β|10>. In the case,the dipole squeezing effect not only depends on the mean photon numbers but also on the degree of entanglement of the two-mode entangled coherent field..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 836 (2006)
Quantum properties of the binomial state field interacting with a cascade three-level atom
Yao-hua HU, Mao-fa FANG, and Chun-lei JIANG
Antibunching effect and squeezing property of the binomial state field interacting with a cascade three-level atom are studied by using quantum theory and calculation method,and the influences of initial field parameters on the quantum properties of the field are discussed. The results are that,firstly,when the field iAntibunching effect and squeezing property of the binomial state field interacting with a cascade three-level atom are studied by using quantum theory and calculation method,and the influences of initial field parameters on the quantum properties of the field are discussed. The results are that,firstly,when the field is initially in a coherent state,its antibunching effect can be displayed discontinuously and squeezing effect can be exhibited in a short time;Secondly,when the initial field is in a middle state between the coherent state and number state,the field shows antibunching effect continuously and the deep degree and sustained time of its squeezing effect increase;Finally,while when the initial field transmits to a fock state,the field reveals continuously antibunching effect but its squeezing effect weakens to disappear. Our results show that binomial state field displays remarkable no-classical properties when it interacts with a cascade three-level atom..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 843 (2006)
Quantum fluctuations of mesoscopic LC circuit at finite temperature
Li-cheng QU, Yu-xi WU, and Qi-liang HE
At a definite temperature,a mesoscopic circuit isn't in a determinate quantum state,but in the mixed state. Using the quantum canonic ensemble theory,the quantum fluctuations of charge and circuit of a mesoscopic LC circuit in the mixed state were studied.It is shown that the quantum fluctuations of a mesoscopic LCAt a definite temperature,a mesoscopic circuit isn't in a determinate quantum state,but in the mixed state. Using the quantum canonic ensemble theory,the quantum fluctuations of charge and circuit of a mesoscopic LC circuit in the mixed state were studied.It is shown that the quantum fluctuations of a mesoscopic LC circuit depend on not only the circuit component parameters,but also the temperature. The higher the temperature,the more quantum noise the mesoscopic LC exhibits. This method is more easily understood and applied than the TFD method. As the mesoscopic circuit is always at finite temperatures,the result is useful for controlling the quantum fluctuations of mesoscopic circuit..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 848 (2006)
Study on the band gap of photonic crystals using phase diagram
Mei-ping JIANG, Xian-feng CHEN, Li TANG, Xiao-ming SHEN, and Du-fang SHI
The phase diagrams are used to ascertain positions of 1 D photonic crystal band gaps. The positions and characteristics of the photonic crystal band gaps can be expediently depicted by using patulous phase diagrams. The band-gap width is largest when the photonic crystal is composed of alternately arranged quarter waveThe phase diagrams are used to ascertain positions of 1 D photonic crystal band gaps. The positions and characteristics of the photonic crystal band gaps can be expediently depicted by using patulous phase diagrams. The band-gap width is largest when the photonic crystal is composed of alternately arranged quarter wave stacks. Increasing the ratio of refractive indices can enlarge the band-gap width. For a conventional photonic crystal,the central position of every band gap will depart from the integral times of the central frequency if the optical thickness of both media in periodic unit is not equal. Furthermore,the transmittance in the central region of the band gap is studied,and the formula of transmittance near the central frequency with the first approximation are deduced. The spectrum line width and quality factor of the Fabry-Perot cavity are qualitatively discussed..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 853 (2006)
Effect of Procaine on photodynamic therapy
Cheng-mei ZHAO, Bin SHEN, Ru-lian FU, and Liang LIU
Objective: ① Observe from outside the body the photodynamic therapy of light sensitive agent CPD5 on human pancreas cancer cells(Hs766T);② Observe the light-generated effect of Procaine on CPD5. Method: add pancreas cancer cells with a concentration of 1×105 ml into a culture panel with 96 holes,each hole 100 μl,tObjective: ① Observe from outside the body the photodynamic therapy of light sensitive agent CPD5 on human pancreas cancer cells(Hs766T);② Observe the light-generated effect of Procaine on CPD5. Method: add pancreas cancer cells with a concentration of 1×105 ml into a culture panel with 96 holes,each hole 100 μl,then add in CPD5 of different concentrations,replace the used cultures with fresh ones 24 hours later. Add Procaine to the Procaine group and physiological saline to the light-generated compare group. Expose each hole to a radiation of 670 nm laser diode with a dose of 10 J/cm2 for 3 minutes. Measure the livability of cells with the dyeing cell experiment after another 24 hours of culture. Result:①The livability of pancreas cancer cells after the PDT is 2.0% when the concentration of CPD5 is at 2.5 μg/ml. ② The light-generated effect of CPD5 with a concentration of 2.5 μg/ml after the addition of Procaine(20 μg/ml)is the livability of pancreas cancer cells is 97.0%.Conclusion: Procaine can greatly decrease the light-generated effect of CPD5..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 858 (2006)
A distributed fast wavelength reservation protocol in wavelength-routed networks
Jian LI, Yan-jun CUI, Peng JIA, Jie ZHANG, and Wan-yi GU
The distributed wavelength reservation protocols are used for wavelength reservation and configuration during the connection setup process. Such protocols proposed so far in the literature all aim to achieve better blocking performance. But no protocol based on local information has been developed to get a shorter setuThe distributed wavelength reservation protocols are used for wavelength reservation and configuration during the connection setup process. Such protocols proposed so far in the literature all aim to achieve better blocking performance. But no protocol based on local information has been developed to get a shorter setup time which is very important in the most dynamic networks in the future. A novel distributed wavelength reservation protocol for wavelength-routed networks,named destination reservation protocol(DRP),is proposed. The connection setup delay is shortened and the messages needed to be processed are reduced. Simulation results reveal that DRP outperforms the other protocols in the literature..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 862 (2006)
Frequency response of silicon-claded proton-exchanged channel waveguides
Ji-jiang WU, Bang-ren SHI, and Mei KONG
The annealed proton-exchanged(APE)process has emerged as an important technique for the fabrication of low-loss optical waveguides in LiNbO3. However,the propagation characteristics of this kind of optical waveguides have not been effectively investigated. The propagation characteristics of a silicon-clad x-cut APE chaThe annealed proton-exchanged(APE)process has emerged as an important technique for the fabrication of low-loss optical waveguides in LiNbO3. However,the propagation characteristics of this kind of optical waveguides have not been effectively investigated. The propagation characteristics of a silicon-clad x-cut APE channel optical waaveguide as a function of wavelength are investigated by the semi-vectorial beam propagation method. Results for several different waveguide parameters are shown. The results obtained show that attenuation of the propagating mode in this waveguides is highly dependent on wavelength. Moreover,this attenuation characteristic can be controlled by waveguide parameters such as the surface refractive index increment,the thickness of silicon-cladding and the thickness and the refractive index of the buffer layer. As a result,the silicon-clad proton-exchanged optical waveguides can be used as optical frequency filters..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 867 (2006)
Current expansion of GaN-based LED and its affection to the device
Chong-qing SUN, De-shu ZOU, Xiao-ling GU, Jian-ming ZHANG, Li-min DONG, Ying-pin SONG, Xia GUO, Guo GAO, and Guang-di SHEN
The current expansion of GaN-based LED is very important to the characteristics of devices. Two kinds of devices were introduced and their merits and drawbacks were compared and the current expansion was introduced. It is pointed out that the ring-N-electrode was propitious to the current expansion and proved by experiThe current expansion of GaN-based LED is very important to the characteristics of devices. Two kinds of devices were introduced and their merits and drawbacks were compared and the current expansion was introduced. It is pointed out that the ring-N-electrode was propitious to the current expansion and proved by experiments. The characteristic of the ring-N-eledtrode was comparied with the common N-electrode,and there was 6% reduction at forward voltage(20 mA). The total radiation power of the device was also improved at the same forward current. When the device worked for 50 hours,the total radiation power of the ring-electrode device was enhanced 8% compared to the traditional device. The contribution of the ring-N-electrode was proved particularly..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 872 (2006)
Effect of crystallization temperature in infilling of InP in SiO2 artificial opals
Wei CHANG, Guang-han FAN, Chun-hua TAN, Shu-ti LI, Yong LEI, Kun HUANG, Pin-qi ZHENG, and Yu-bin CHEN
SiO2 artificial opal templates are fabricated,and metal organic chemical vapour deposition is used to infill the voids of prepared silica colloidal crystals with InP. The samples are characterized by scanning electron microscopy and UV-VIS spectroscopy. The results show that the crystallization temperature is an importSiO2 artificial opal templates are fabricated,and metal organic chemical vapour deposition is used to infill the voids of prepared silica colloidal crystals with InP. The samples are characterized by scanning electron microscopy and UV-VIS spectroscopy. The results show that the crystallization temperature is an important factor in the infilling of InP. By the increasing of crystallization temperature,the infilling ratio of InP decreases..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 876 (2006)
Direct analysis in time domain method for TW electrode on InP/InGaAsP-EAM
Chun CAI, Xu LIU, Jin-biao XIAO, Ming-de ZHANG, and Xiao-han SUN
Traveling wave(TW)electrode structure is widely used for it needs less multi-action length between optical carrier and digital modulation and can get rid of contribution capacity's constraints on modulation bandwidth. Based on time domain method,TW electrode on InP/InGaAsP electronic absorption modulator is simulatTraveling wave(TW)electrode structure is widely used for it needs less multi-action length between optical carrier and digital modulation and can get rid of contribution capacity's constraints on modulation bandwidth. Based on time domain method,TW electrode on InP/InGaAsP electronic absorption modulator is simulated,analyzed and compared with the fabrication on characteristic impedance Zc and loss coefficient α. The numeric results calculated by time domain method coincide with measurement well. Characteristic impedance is about 45Ω,and the loss coefficient is less than 4 dB/mm from DC to 20 GHz..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 12, 2021
- Vol. 23, Issue 6, 881 (2006)
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