Volume 1,Issue 3,2005 Table of Contents
2005, 1(3).
Abstract:
2005, 1(3).
Abstract:
2005, 1(3).
Abstract:
2005, 1(3).
Abstract:
2005, 1(3).
Abstract:
2005, 1(3):i.
Abstract:
A new Chinese journal,Optoelectronics Letters(in English),has been published on15July2005as the companion journal to Journal of Optoelectronics,Laser(the core journal in Chinese).The aim is rapid dissemination of new important results in the fields of Optoelectronics/Photonics from China and other countries to advanced the international academic exchanges.Optoelectronics Letters will pay a special attention to combing optics(photonics)with electronics.The scope of the journal can be found…
A new Chinese journal,Optoelectronics Letters(in English),has been published on15July2005as the companion journal to Journal of Optoelectronics,Laser(the core journal in Chinese).The aim is rapid dissemination of new important results in the fields of Optoelectronics/Photonics from China and other countries to advanced the international academic exchanges.Optoelectronics Letters will pay a special attention to combing optics(photonics)with electronics.The scope of the journal can be found…
2005, 1(3):161-163.
Abstract:
A new type of high-power broadband superfluorescent source of Yb3+-doped double-cladding photonic crystal fiber is reported experimentally, which is pumped at 976 nm by a high-power laser diode with the end-coupling method. We have obtained a smooth broadband output of superfluorescence. The maximum output power is 1.649 W with a slope efficiency of 56.7%. The 3 dB bandwidth is 22.4 nm. To the best of our knowledge, this is the first report about SFS with such high output power of 1.649 W. This work was supported by the National Natural Science Foundation under Grant No. 60377010, the “973” Project under Grant No. 2003CG314906 and the Research Fund for Doctoral Programme for Higher Education under Grant No. 2003005016.
A new type of high-power broadband superfluorescent source of Yb3+-doped double-cladding photonic crystal fiber is reported experimentally, which is pumped at 976 nm by a high-power laser diode with the end-coupling method. We have obtained a smooth broadband output of superfluorescence. The maximum output power is 1.649 W with a slope efficiency of 56.7%. The 3 dB bandwidth is 22.4 nm. To the best of our knowledge, this is the first report about SFS with such high output power of 1.649 W. This work was supported by the National Natural Science Foundation under Grant No. 60377010, the “973” Project under Grant No. 2003CG314906 and the Research Fund for Doctoral Programme for Higher Education under Grant No. 2003005016.
2005, 1(3):164-167.
Abstract:
A theoretical calculation for the temperature dependence of the excitonic transition in ZnSe/ZnOdSe quantum wells is performed. The exciton binding energy is calculated with a variational technique by considering the temperature-dependence parameters. Our results show that the exciton binding energy reduces linearly with temperature increasing. We find that the strain due to lattice mismatch and differential thermal expansion decreases with the temperature increasing.
A theoretical calculation for the temperature dependence of the excitonic transition in ZnSe/ZnOdSe quantum wells is performed. The exciton binding energy is calculated with a variational technique by considering the temperature-dependence parameters. Our results show that the exciton binding energy reduces linearly with temperature increasing. We find that the strain due to lattice mismatch and differential thermal expansion decreases with the temperature increasing.
2005, 1(3):168-171.
Abstract:
The shear lag theory is used to analyze the stress transfer from concrete matrix to FBG sensors based on that the FBG sensor and the concrete matrix are composite. The stress transfer formula and the coefficient are obtained. The experiments prove that the theoretical results of the stress transfer by the stress transfer formula are in well agreement with the experimental data.
The shear lag theory is used to analyze the stress transfer from concrete matrix to FBG sensors based on that the FBG sensor and the concrete matrix are composite. The stress transfer formula and the coefficient are obtained. The experiments prove that the theoretical results of the stress transfer by the stress transfer formula are in well agreement with the experimental data.
2005, 1(3):172-174.
Abstract:
In this letter, a theoretical model of radiation-balanced double clad fiber laser is presented. The characteristic of the laser with Yb doped double clad fiber is analyzed numerically. It is concluded that high output laser power can be obtained by selecting output coupling mirror with lower reflectivity, improving Yb doped concentration and choosing fiber length. This result can help us to design radiation balanced fiber laser.
In this letter, a theoretical model of radiation-balanced double clad fiber laser is presented. The characteristic of the laser with Yb doped double clad fiber is analyzed numerically. It is concluded that high output laser power can be obtained by selecting output coupling mirror with lower reflectivity, improving Yb doped concentration and choosing fiber length. This result can help us to design radiation balanced fiber laser.
2005, 1(3):175-178.
Abstract:
A novel discharge device is designed on the basis of the configuration of micro-hollow cathode discharge (MHCD). By using many MHCDs in parallel connection, a micro-discharge array can be constructed. With the micro-discharge array, a high-pressure high-current density glow discharge plasmas can be formed to make a plasma display panel (PDP). An air discharge experiment is finished with the discharge device. The stable direct current glow discharge is formed under the pressure from 20 Torr to 500 Torr. The voltage-current characteristic curve and the discharge photograph are noted. The voltage-current characteristic curve has a positive differential resistance coefficient on the whole discharge range. The estimated current density reaches 70. 1A/cm3, the power density is 3.6 × 104 W/cm3, and the electron density is in the order of 1013 cm−3 atp=200 Torr andI D=10 mA. The experimental results indicate that the designed discharge device is appropriate for PDP.
A novel discharge device is designed on the basis of the configuration of micro-hollow cathode discharge (MHCD). By using many MHCDs in parallel connection, a micro-discharge array can be constructed. With the micro-discharge array, a high-pressure high-current density glow discharge plasmas can be formed to make a plasma display panel (PDP). An air discharge experiment is finished with the discharge device. The stable direct current glow discharge is formed under the pressure from 20 Torr to 500 Torr. The voltage-current characteristic curve and the discharge photograph are noted. The voltage-current characteristic curve has a positive differential resistance coefficient on the whole discharge range. The estimated current density reaches 70. 1A/cm3, the power density is 3.6 × 104 W/cm3, and the electron density is in the order of 1013 cm−3 atp=200 Torr andI D=10 mA. The experimental results indicate that the designed discharge device is appropriate for PDP.
2005, 1(3):179-181.
Abstract:
In this paper we describe a full-integrated circuit containing all building blocks of a completed PLL-based synthesizer except for low pass filter (LPF). The frequency synthesizer is designed for a frequency hopping (FH) transceiver operating up to 1.5 GHz as a local oscillator. The architecture of Voltage Controlled Oscillator (VCO) is optimized to get better performance, and a phase noise of −111.85-dBc/Hz @ 1 MHz and a tuning range of 250 MHz are gained at a centre frequency of 1.35 GHz. A novel Dual-Modulus Prescaler (DMP) is designed to achieve a very low jitter and a lower power. The settling time of PLL is 80 μs while the reference frequency is 400 KHz. This monolithic frequency synthesizer is to integrate all main building blocks of PLL except for the low pass filter, with a maximum VCO output frequency of 1.5 GHz, and is fabricated with a 0.18 μm mixed signal CMOS process. Low power dissipation, low phase noise, large tuning range and fast settling time are gained in this design.
In this paper we describe a full-integrated circuit containing all building blocks of a completed PLL-based synthesizer except for low pass filter (LPF). The frequency synthesizer is designed for a frequency hopping (FH) transceiver operating up to 1.5 GHz as a local oscillator. The architecture of Voltage Controlled Oscillator (VCO) is optimized to get better performance, and a phase noise of −111.85-dBc/Hz @ 1 MHz and a tuning range of 250 MHz are gained at a centre frequency of 1.35 GHz. A novel Dual-Modulus Prescaler (DMP) is designed to achieve a very low jitter and a lower power. The settling time of PLL is 80 μs while the reference frequency is 400 KHz. This monolithic frequency synthesizer is to integrate all main building blocks of PLL except for the low pass filter, with a maximum VCO output frequency of 1.5 GHz, and is fabricated with a 0.18 μm mixed signal CMOS process. Low power dissipation, low phase noise, large tuning range and fast settling time are gained in this design.
2005, 1(3):182-184.
Abstract:
CRT Corner cutting tube is considered as a definitive reject and will be sent to reclaim at all times. It caused lots of material loss. In this paper, a novel technology used to save CRTs corner cutting tube is presented firstly. A set of repair system has been successfully developed to repair CRTs corner cutting tube. Then, the process technology for corner cutting repair has been excogitated by empirical studies. Finally, the correlative performances of repaired tube are evaluated. The experimental results show that the quality of repaired tube has no difference with that of normal product. The repair yield has reached above 97 percent. This new technology has contributed to improving the production yield, reducing the material consumption and decreasing the cost of color CRT production.
CRT Corner cutting tube is considered as a definitive reject and will be sent to reclaim at all times. It caused lots of material loss. In this paper, a novel technology used to save CRTs corner cutting tube is presented firstly. A set of repair system has been successfully developed to repair CRTs corner cutting tube. Then, the process technology for corner cutting repair has been excogitated by empirical studies. Finally, the correlative performances of repaired tube are evaluated. The experimental results show that the quality of repaired tube has no difference with that of normal product. The repair yield has reached above 97 percent. This new technology has contributed to improving the production yield, reducing the material consumption and decreasing the cost of color CRT production.
2005, 1(3):185-187.
Abstract:
The structure of the optical waveguide of 2-bit electrooptic A/D converter with proton-exchange micro prisms is optimized by the finite-difference beam propagation method (FD-BPM). The electrode parameters of the converter are optimized by conformal mapping. The optimal parameters are a halfwave voltage ofV π =4.5V and a bandwidth of Δf=1.4 GHz. A normalized transmitted power of 69.75% is obtained by FD-BMP and the output waveguide gap is 300 μm.
The structure of the optical waveguide of 2-bit electrooptic A/D converter with proton-exchange micro prisms is optimized by the finite-difference beam propagation method (FD-BPM). The electrode parameters of the converter are optimized by conformal mapping. The optimal parameters are a halfwave voltage ofV π =4.5V and a bandwidth of Δf=1.4 GHz. A normalized transmitted power of 69.75% is obtained by FD-BMP and the output waveguide gap is 300 μm.
2005, 1(3):188-190.
Abstract:
A new, simple and efficient fiber audio transmission method for the long distance secure communication is presented, which performs signal modulation by the strain-optic effects and signal demodulation by the all-fiber interferometer. The interferometer is a truly path-matched device, which eliminates much of the undesirable noise by combining the reference and the sensing arms within the same optical fiber. The sinusoidal signals adopted in the experiment are in a frequency range of 300 HZ-3 400 HZ and of the multi-frequency, and the system shows good capabilities, robust security and maintenance of audio integrity. The device may be applicable in the field of point to point secure communication of 40 kilometer long transmission range.
A new, simple and efficient fiber audio transmission method for the long distance secure communication is presented, which performs signal modulation by the strain-optic effects and signal demodulation by the all-fiber interferometer. The interferometer is a truly path-matched device, which eliminates much of the undesirable noise by combining the reference and the sensing arms within the same optical fiber. The sinusoidal signals adopted in the experiment are in a frequency range of 300 HZ-3 400 HZ and of the multi-frequency, and the system shows good capabilities, robust security and maintenance of audio integrity. The device may be applicable in the field of point to point secure communication of 40 kilometer long transmission range.
2005, 1(3):191-193.
Abstract:
In order to gain circularly polarized light of left-handed and right-handed rotation by using a fixed device, a left-handed and right-handed rotation double function circular polarizer is designed with two ν/4 retarders and one polarizer, and its operating principle is analysed by matrix optical means. The result indicates that when the monochromatic light enters this circular polarizer in the positive direction and the negative direction, the emergent light should be circularly polarized light, of left-handed and right-handed rotation respectively. The testing system has been established to verify the above results.
In order to gain circularly polarized light of left-handed and right-handed rotation by using a fixed device, a left-handed and right-handed rotation double function circular polarizer is designed with two ν/4 retarders and one polarizer, and its operating principle is analysed by matrix optical means. The result indicates that when the monochromatic light enters this circular polarizer in the positive direction and the negative direction, the emergent light should be circularly polarized light, of left-handed and right-handed rotation respectively. The testing system has been established to verify the above results.
2005, 1(3):194-197.
Abstract:
In this paper, the effects of shapes and orientations of rods on absolute PBGs in 2D square lattice are studied. By replacing round rods with square rods, which sides are along with the direction of elementary lattices vectors, the absolute PBGs in 2D square lattice with wave vector in periodic plane and off periodic plane have been studied and then through changing the square rods orientation, the changing of the width and position of PBG has been obtained.
In this paper, the effects of shapes and orientations of rods on absolute PBGs in 2D square lattice are studied. By replacing round rods with square rods, which sides are along with the direction of elementary lattices vectors, the absolute PBGs in 2D square lattice with wave vector in periodic plane and off periodic plane have been studied and then through changing the square rods orientation, the changing of the width and position of PBG has been obtained.
2005, 1(3):198-200.
Abstract:
The band gap properties of one-dimensional photonic crystals with a defect layer of negative refractive index materials are studied. The defect mode width is bigger than that of conventional one-dimensional photonic crystals with a defect layer of positive refractive index materials. The defect mode of the former is different from that of the latter, shifts towards the direction of high frequency (short wavelength), and has a bigger shifting velocity. Furthermore the effects on the transmission properties of the former photonic crystals caused by change in the position of the defect layer of negative refractive index are investigated. Finally the optical enhancement of the former photonic crystals is also investigated.
The band gap properties of one-dimensional photonic crystals with a defect layer of negative refractive index materials are studied. The defect mode width is bigger than that of conventional one-dimensional photonic crystals with a defect layer of positive refractive index materials. The defect mode of the former is different from that of the latter, shifts towards the direction of high frequency (short wavelength), and has a bigger shifting velocity. Furthermore the effects on the transmission properties of the former photonic crystals caused by change in the position of the defect layer of negative refractive index are investigated. Finally the optical enhancement of the former photonic crystals is also investigated.
19 Transmission spectra of one-dimensional photonic crystals including negative-refractive-index media
2005, 1(3):201-204.
Abstract:
We introduce a new model of one-dimensional (1D) photonic crystal composed of alternately arranged RHM and LHM layers with positive and negative refractive indices respectively, for which the transmission spectra of the model are calculated numerically with the transfer matrix method, and the bandgap structure and the polarization properties are analyzed. We found that the introduction of negative refractive index layers (i.e. LHM medium layers) gives rise to some peculiar band—gap structure and polarization properties as follows. Firstly, the forbidden bands are extremely wide and the transmission bands are very sharp without oscillation; and secondly, the change of incident angle has different influences on the forbidden bands of TE and TM modes. For the TM mode, the forbidden band width decreases substantially and finally vanishes, and for the TE mode with central wavelength, the total reflection happens at any incident angle.
We introduce a new model of one-dimensional (1D) photonic crystal composed of alternately arranged RHM and LHM layers with positive and negative refractive indices respectively, for which the transmission spectra of the model are calculated numerically with the transfer matrix method, and the bandgap structure and the polarization properties are analyzed. We found that the introduction of negative refractive index layers (i.e. LHM medium layers) gives rise to some peculiar band—gap structure and polarization properties as follows. Firstly, the forbidden bands are extremely wide and the transmission bands are very sharp without oscillation; and secondly, the change of incident angle has different influences on the forbidden bands of TE and TM modes. For the TM mode, the forbidden band width decreases substantially and finally vanishes, and for the TE mode with central wavelength, the total reflection happens at any incident angle.
2005, 1(3):205-208.
Abstract:
Micro-structures 3-D profile measurement is an important measurement content for research on micromachining and characterization of micro-dimension. In this paper, a new method involved 2-D structure template, which guides phase unwrapping, is proposed based on phase-shifting microscopic interferometry. It is fit not only for static measurement but also for dynamic measurement, especially for motion of MEMS devices. 3-D profile of active comb of micro-resonator is obtained by using the method. The theoretic precision in out-of-plane direction is better than 0.5 nm. The in-plane, theoretic precision in micro-structures is better than 0.5 μm. But at the edge of micro-structures, it is on the level of micrometer mainly caused by imprecise edge analysis. Finally, its disadvantages and the following development are discussed. Supported: Tianjin Important Science and Technology Project (043185911) and National High-Technology Research and Development Project (863 project) in China (2004AA404042).
Micro-structures 3-D profile measurement is an important measurement content for research on micromachining and characterization of micro-dimension. In this paper, a new method involved 2-D structure template, which guides phase unwrapping, is proposed based on phase-shifting microscopic interferometry. It is fit not only for static measurement but also for dynamic measurement, especially for motion of MEMS devices. 3-D profile of active comb of micro-resonator is obtained by using the method. The theoretic precision in out-of-plane direction is better than 0.5 nm. The in-plane, theoretic precision in micro-structures is better than 0.5 μm. But at the edge of micro-structures, it is on the level of micrometer mainly caused by imprecise edge analysis. Finally, its disadvantages and the following development are discussed. Supported: Tianjin Important Science and Technology Project (043185911) and National High-Technology Research and Development Project (863 project) in China (2004AA404042).
21 Numerical analysis of thermal distortion of the mirror in space-to-ground laser communication links
2005, 1(3):209-212.
Abstract:
The thermal distortion of an optical reflector surface due to the changing sunlight in a space environment will cause shift and spreading of its reflected focus and thereby influence the performance of space-to-ground laser communication links. Based on the characteristics of a low orbit satellite, the normal shift of a plan mirror caused by thermal distortion is analyzed with the software of the ANSYS of finite element analysis. A general expression of the transmitted beam from a distorted reflector surface and a counting formula for the shifts of the focus center before and after thermal distortion are deduced. The result of simulation shews that the magnitude order of the normal shift of the antenna mirror surface can be as high as tens of urad. The worse the mirror thermal distortion is, the larger the shift of the received focus center is. And the change of the shifts does not obey a linear rule.
The thermal distortion of an optical reflector surface due to the changing sunlight in a space environment will cause shift and spreading of its reflected focus and thereby influence the performance of space-to-ground laser communication links. Based on the characteristics of a low orbit satellite, the normal shift of a plan mirror caused by thermal distortion is analyzed with the software of the ANSYS of finite element analysis. A general expression of the transmitted beam from a distorted reflector surface and a counting formula for the shifts of the focus center before and after thermal distortion are deduced. The result of simulation shews that the magnitude order of the normal shift of the antenna mirror surface can be as high as tens of urad. The worse the mirror thermal distortion is, the larger the shift of the received focus center is. And the change of the shifts does not obey a linear rule.
22 Double-theodolite measurement system used in the image calibration of space photographic instrument
2005, 1(3):213-216.
Abstract:
The purpose of characterizing the image of space photographic instrument is to gain the space included angles from three coordinate axes in the three-dimensional coordinate of the image and the directionality of the three axes of coordinate in the frame of axes of the instrument. The two reference frames will keep in the same direction finally by adjusting according to space angles. This problem was solved by a new high-precision measurement system composed of a double-theodolite and a set of communication system. In the survey system, two TDA5005 total stations from Leica Company will be selected as the double-theodolite and the interdependence of both coordinate systems can be achieved by moving the stations only at one time. Therefore, this measurement system provides a highly efficient and high-precision surveying method to the image calibration of the space photographic instrument. According to the experiment, its measuring accuracy can reach arc-second level.
The purpose of characterizing the image of space photographic instrument is to gain the space included angles from three coordinate axes in the three-dimensional coordinate of the image and the directionality of the three axes of coordinate in the frame of axes of the instrument. The two reference frames will keep in the same direction finally by adjusting according to space angles. This problem was solved by a new high-precision measurement system composed of a double-theodolite and a set of communication system. In the survey system, two TDA5005 total stations from Leica Company will be selected as the double-theodolite and the interdependence of both coordinate systems can be achieved by moving the stations only at one time. Therefore, this measurement system provides a highly efficient and high-precision surveying method to the image calibration of the space photographic instrument. According to the experiment, its measuring accuracy can reach arc-second level.
2005, 1(3):217-220.
Abstract:
The main goal of routing solutions is to satisfy the requirements of the Quality of Service (QoS) for every admitted connection as well as to achieve a global efficiency in resource utilization. In this paper proposes a solution based on Hopfield neural network (HNN) to deal with one of representative routing problems in uni-cast routing, i. e. the multi-constrained (MC) routing problem. Computer simulation shows that we can obtain the optimal path very rapidly with our new Lyapunov energy functions. This work is supported by National Natural Science Foundation of China (No. 60277022), Outstanding Youth Foundation of Henan Province, Natural Science Foundation of Tianjin (No. 023800811), the Research Fund for the Doctoral Program of Higher education (No.20030055022). The Project-sponsored by SRF for ROCS, SEM.
The main goal of routing solutions is to satisfy the requirements of the Quality of Service (QoS) for every admitted connection as well as to achieve a global efficiency in resource utilization. In this paper proposes a solution based on Hopfield neural network (HNN) to deal with one of representative routing problems in uni-cast routing, i. e. the multi-constrained (MC) routing problem. Computer simulation shows that we can obtain the optimal path very rapidly with our new Lyapunov energy functions. This work is supported by National Natural Science Foundation of China (No. 60277022), Outstanding Youth Foundation of Henan Province, Natural Science Foundation of Tianjin (No. 023800811), the Research Fund for the Doctoral Program of Higher education (No.20030055022). The Project-sponsored by SRF for ROCS, SEM.
2005, 1(3):221-223.
Abstract:
A low-loss fiber optic rotary joint (FORJ) has been designed by using two kinds of C-lens collimators. Its insertion loss and insertion loss variation due to rotation with single-mode fiber collimator is less than 1.76 dB and 0.43 dB respectively. The maximum insertion loss and coupling variation due to rotation with multi-mode fiber collimator is 1.71 dB and 0.29 dB, respectively. This kind of FORJ features low insertion loss, small coupling variation due to rotation and low cost. This work was supported by the National Natural Science Foundation of China under contract No. 60377031, and National Basic Research Program of China under contract No. 2003CB314907.
A low-loss fiber optic rotary joint (FORJ) has been designed by using two kinds of C-lens collimators. Its insertion loss and insertion loss variation due to rotation with single-mode fiber collimator is less than 1.76 dB and 0.43 dB respectively. The maximum insertion loss and coupling variation due to rotation with multi-mode fiber collimator is 1.71 dB and 0.29 dB, respectively. This kind of FORJ features low insertion loss, small coupling variation due to rotation and low cost. This work was supported by the National Natural Science Foundation of China under contract No. 60377031, and National Basic Research Program of China under contract No. 2003CB314907.
2005, 1(3):224-227.
Abstract:
According to the principle of polarization imaging and the relation between Stokes parameters and the degree of linear polarization, there are much redundant and complementary information in polarized images. Since man-made objects and natural objects can be easily distinguished in images of degree of linear polarization and images of Stokes parameters contain rich detailed information of the scene, the clutters in the images can be removed efficiently while the detailed information can be maintained by combining these images. An algorithm of adaptive polarization image fusion based on regional energy dynamic weighted average is proposed in this paper to combine these images. Through an experiment and simulations, most clutters are removed by this algorithm. The fusion method is used for different light conditions in simulation, and the influence of lighting conditions on the fusion results is analyzed.
According to the principle of polarization imaging and the relation between Stokes parameters and the degree of linear polarization, there are much redundant and complementary information in polarized images. Since man-made objects and natural objects can be easily distinguished in images of degree of linear polarization and images of Stokes parameters contain rich detailed information of the scene, the clutters in the images can be removed efficiently while the detailed information can be maintained by combining these images. An algorithm of adaptive polarization image fusion based on regional energy dynamic weighted average is proposed in this paper to combine these images. Through an experiment and simulations, most clutters are removed by this algorithm. The fusion method is used for different light conditions in simulation, and the influence of lighting conditions on the fusion results is analyzed.
2005, 1(3):228-231.
Abstract:
In this paper we propose a three dimensional multiplierless discrete cosine transform (DCT) with lifting scheme called 3D-binDCT. Based on 3D-binDCT, a novel video coding algorithm without motion estimation/compensation is proposed. It uses the 3D-binDCT to exploit spatial or temporal redundancy. The computation of binDCT only needs shift and addition operations, thus the computational complexity is minimized. DC coefficient prediction, modified scan mode and arithmetic coding techniques are also adopted. Extensive simulation results show that the proposed coding scheme provides higher coding efficiency and improves visual quality, and it is easy to be realized by software and hardware. This work is supported by the National Science Foundation of China (60572152)
In this paper we propose a three dimensional multiplierless discrete cosine transform (DCT) with lifting scheme called 3D-binDCT. Based on 3D-binDCT, a novel video coding algorithm without motion estimation/compensation is proposed. It uses the 3D-binDCT to exploit spatial or temporal redundancy. The computation of binDCT only needs shift and addition operations, thus the computational complexity is minimized. DC coefficient prediction, modified scan mode and arithmetic coding techniques are also adopted. Extensive simulation results show that the proposed coding scheme provides higher coding efficiency and improves visual quality, and it is easy to be realized by software and hardware. This work is supported by the National Science Foundation of China (60572152)
2005, 1(3):232-234.
Abstract:
A newe class of multilength, constant-weight and two-dimensional multiwavelength optical orthogonal code (2D MWOOCs) with large capacity and good correlation properties is constructed based on multilength one-dimensional (1D) OOCs. The performance of these newe MWOOCs in an OCDMA network with double-services is analyzed. The result shows that media with the shorter codeword performs much better than the media with longer codeword, and OCDMA system with these new multilength MWOOCs performs well. These features allow multimedia transmission of large capacity in OCDMA
A newe class of multilength, constant-weight and two-dimensional multiwavelength optical orthogonal code (2D MWOOCs) with large capacity and good correlation properties is constructed based on multilength one-dimensional (1D) OOCs. The performance of these newe MWOOCs in an OCDMA network with double-services is analyzed. The result shows that media with the shorter codeword performs much better than the media with longer codeword, and OCDMA system with these new multilength MWOOCs performs well. These features allow multimedia transmission of large capacity in OCDMA
2005, 1(3):235-237.
Abstract:
A feature-constrained stereo matching algorithm for lunar rover navigation is presented based on the analysis of the stereo vision system and working environments of lunar rover. In feature-matching phase, edge points are extracted with wavelet transform and are used as the primitives for matching. Then three criterions are utilized in turn to select the correct matching points with the pyramidal searching strategy. As a result, the algorithm finds corresponding points successfully for large numbers of edge points. Area-matching is accomplished under the constraint of edge-matching results, and the correlation is selected as the criterion. Experimental results with real images of natural terrain indicate that the algorithm provides dense disparity maps with fairly high accuracy.
A feature-constrained stereo matching algorithm for lunar rover navigation is presented based on the analysis of the stereo vision system and working environments of lunar rover. In feature-matching phase, edge points are extracted with wavelet transform and are used as the primitives for matching. Then three criterions are utilized in turn to select the correct matching points with the pyramidal searching strategy. As a result, the algorithm finds corresponding points successfully for large numbers of edge points. Area-matching is accomplished under the constraint of edge-matching results, and the correlation is selected as the criterion. Experimental results with real images of natural terrain indicate that the algorithm provides dense disparity maps with fairly high accuracy.
2005, 1(3):238-240.
Abstract:
The spectra of fiber Bragg grating (FBG) in inhomogeneous strain fields are distorted due to its inhomogeneity of both the periods and the effective refractive index. The couple mode theory and the Runge-Kutta method can be employed for exact simulation of the spectrum of Bragg grating in such field, but the convergence speed is slow. On the other hand, although the transfer matrix method could be used with higher convergence speed, the precision is poor because of the neglect of the grads of strain change. By improving the FBG equivalent period, a novel simulation method based on a modified transfer matrix method is proposed, which has the advantage of quick-convergence as well as good accuracy. This work is supported by Jiangsu Province Natural Science Foundation of China under project BK2004207 and the National Science Fund for Distinguished Young Scholars under project 60125513.
The spectra of fiber Bragg grating (FBG) in inhomogeneous strain fields are distorted due to its inhomogeneity of both the periods and the effective refractive index. The couple mode theory and the Runge-Kutta method can be employed for exact simulation of the spectrum of Bragg grating in such field, but the convergence speed is slow. On the other hand, although the transfer matrix method could be used with higher convergence speed, the precision is poor because of the neglect of the grads of strain change. By improving the FBG equivalent period, a novel simulation method based on a modified transfer matrix method is proposed, which has the advantage of quick-convergence as well as good accuracy. This work is supported by Jiangsu Province Natural Science Foundation of China under project BK2004207 and the National Science Fund for Distinguished Young Scholars under project 60125513.
2005, 1(3):F0003-F0003.
Abstract:
Optoelectronics Letters is the companion journal to Journal of Optoelectronics ,Laser (the core journal in Chinese) The purpose of Optoelectronics Letters is rapid reporting new important results in the fields of optoelectronics /photonics in English to advanced the international academic exchangesThe scope of Optoelectronics Letters is as follows:Novel oe-devices and applications:New materials and functional components: Micro-nano-structures and integrated optoelectronics: Nano-quantum optoelectronics: information optoelectronic technology;Sensing measurement and inspection; Storage and display; Image and information processing: Biomedical photonics. etc.Submission of manuscriptsThe submitted manuscripts should be the original work of the authors that has not been previously published in a ref-ereed journal and it is not currently under consideration for publication elsewhereEach manuscript should be four the journal pagesThe text of the manuscript is prepared by using Microsoft Word, and should be typed on one side only of A4 pages using font size 10.5 of Times New Roman typeface.It is needed to submit one original and a disk of the manuscript to the editorial office(263 South-Hongqi Road. Nankai District. Tianjin 300191. China) The manuscripts can also be submitted by e-mail to oel@263. net or oelett @yahoo com. cn.It is welcome to suggest possible reviewers for the manuscript, with full information on the postal and e-mail addresses, telephone and fax numbers
Optoelectronics Letters is the companion journal to Journal of Optoelectronics ,Laser (the core journal in Chinese) The purpose of Optoelectronics Letters is rapid reporting new important results in the fields of optoelectronics /photonics in English to advanced the international academic exchangesThe scope of Optoelectronics Letters is as follows:Novel oe-devices and applications:New materials and functional components: Micro-nano-structures and integrated optoelectronics: Nano-quantum optoelectronics: information optoelectronic technology;Sensing measurement and inspection; Storage and display; Image and information processing: Biomedical photonics. etc.Submission of manuscriptsThe submitted manuscripts should be the original work of the authors that has not been previously published in a ref-ereed journal and it is not currently under consideration for publication elsewhereEach manuscript should be four the journal pagesThe text of the manuscript is prepared by using Microsoft Word, and should be typed on one side only of A4 pages using font size 10.5 of Times New Roman typeface.It is needed to submit one original and a disk of the manuscript to the editorial office(263 South-Hongqi Road. Nankai District. Tianjin 300191. China) The manuscripts can also be submitted by e-mail to oel@263. net or oelett @yahoo com. cn.It is welcome to suggest possible reviewers for the manuscript, with full information on the postal and e-mail addresses, telephone and fax numbers
External Links