Journals >Chinese Optics Letters
Contents
2005
Volume: 3 Issue 4
20 Article(s)
Export citation format
Fiber Optics and Optical Communications
Performance of optical amplifier employing silica host magnesium-aluminum-germanium co-doped erbium-doped fiber
Yongjun Fu, Kai Zheng, Wei Jian, and Shuisheng Jian
Two silica host magnesium(Mg)-aluminum(Al)-germanium(Ge) co-doped erbium-doped fibers (EDFs) have been fabricated, which have different Mg concentrations. The concentration of all the compositions in the preform is measured through electronics probe micro analysis (EPMA). The maximum Mg concentrations of fibers A and BTwo silica host magnesium(Mg)-aluminum(Al)-germanium(Ge) co-doped erbium-doped fibers (EDFs) have been fabricated, which have different Mg concentrations. The concentration of all the compositions in the preform is measured through electronics probe micro analysis (EPMA). The maximum Mg concentrations of fibers A and B are 3.98 and 1.28 mol%, respectively. The performance characteristics including absorption spectrum and gain are measured and analyzed. The absorption coefficients of fibers A and B are 13.3 and 14.3 dB/m respectively at wavelength of 1532 nm. The max gains of these two erbium-doped fiber amplifiers (EDFAs) are 30.1 and 35.9 dB with input signal power of -30 dBm and pump power of 100 mW at 980 nm. Fiber B with maximum Mg concentration 1.28 mol% has better performance than fiber A. Fiber B has high absorption coefficient and high gain characteristics. The optimum fiber B length of C-band EDFA is 7 m and that of L-Band EDFA is about 30 m, which is much shorter than standard commercial EDFAs. The result of experiments showed that a few Mg added to silica host EDF can increase the concentration of erbium ions, which will shorten the EDF length much, but not degrade the performance characteristics..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04187 (2005)
Experimental study of nonlinear switching characteristics of conventional 2*2 fused tapered couplers
Feng Liu, Qing Ye, Aiping Luo, Jianrong Qiu, Congshan Zhu, Ronghui Qu, and Zujie Fang
The nonlinear switching characteristics of fused fiber directional couplers were studied experimentally. By using femtosecond laser pulses with pulse width of 100 fs and wavelength of about 1550 nm from a system of Ti:sapphire laser and optical parametric amplifier (OPA), the nonlinear switching properties of a null coThe nonlinear switching characteristics of fused fiber directional couplers were studied experimentally. By using femtosecond laser pulses with pulse width of 100 fs and wavelength of about 1550 nm from a system of Ti:sapphire laser and optical parametric amplifier (OPA), the nonlinear switching properties of a null coupler and a 100% coupler were measured. The experimental results were coincident with the simulations based on nonlinear propagation equations in fiber by using super-mode theory. Nonlinear loss in fiber was also measured to get the injected power at the coupler. After deducting the nonlinear loss and input efficiency, the nonlinear switching critical peak powers for a 100% and a null fused couplers were calculated to be 9410 and 9440 W, respectively. The nonlinear loss parameter P_(N) in an expression of α_(NL)=αP/P_(N) was obtained to be P_(N)=0.23 W..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04190 (2005)
High speed fiber-based clock enhancement of NRZ data
Tong Wu, and Kun Qiu
A scheme for all-fiber clock enhancement of non-return-to-zero (NRZ) data based on cross-phase modulation (XPM) effect in nonlinear fibers is proposed and demonstrated in simulation. The simulation results indicate that the clock-to-data ratio of NRZ signals at 64 Gb/s can be increased to 22.94 dB by using this scheme,A scheme for all-fiber clock enhancement of non-return-to-zero (NRZ) data based on cross-phase modulation (XPM) effect in nonlinear fibers is proposed and demonstrated in simulation. The simulation results indicate that the clock-to-data ratio of NRZ signals at 64 Gb/s can be increased to 22.94 dB by using this scheme, and the pattern effect in clock enhanced signals is very weak. The ability of high speed operation up to 140 Gb/s of this scheme is also proved in our simulation..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04193 (2005)
Performance of a distributed WR-OBS control architecture
Zhou Lan, Hongxiang Guo, Jian Wu, and Jintong Lin
This paper proposes a new distributed wavelength-routed optical burst switching (WR-OBS) network architecture and two corresponding control protocols. By taking advantage of merits from both just enough time (JET) protocol and two-way signaling method, this new control architecture outperforms traditional JET OBS netwoThis paper proposes a new distributed wavelength-routed optical burst switching (WR-OBS) network architecture and two corresponding control protocols. By taking advantage of merits from both just enough time (JET) protocol and two-way signaling method, this new control architecture outperforms traditional JET OBS network in points of burst loss probability, system throughput and centralized WR-OBS network in network scalability confirmed by computer simulations. Further simulation is developed to compare the performance of the two control protocols, which leads to instructive discussion in real WR-OBS network design..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04196 (2005)
A new prediction method at the edge of optical burst switching network
Zhicheng Sui, Qingji Zeng, and Shilin Xiao
To achieve lower assembly delay at optical burst switching edge node, this paper proposes an approach called current weight length prediction (CWLP) to improve existing estimate mechanism in burst assembly. CWLP method takes into account the arrived traffic in prediction time adequately. A parameter `weight' is intTo achieve lower assembly delay at optical burst switching edge node, this paper proposes an approach called current weight length prediction (CWLP) to improve existing estimate mechanism in burst assembly. CWLP method takes into account the arrived traffic in prediction time adequately. A parameter `weight' is introduced to make a dynamic tradeoff between the current and past traffic under different offset time. Simulation results show that CWLP can achieve a significant improvement in terms of traffic estimation in various offset time and offered load..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04199 (2005)
Image Processing
Color fusion of SAR and FLIR images using a natural color transfer technique
Shaoyuan Sun*, Zhongliang Jing, Zhenhua Li, and Gang Liu
Fusion of synthetic aperture radar (SAR) and forward looking infrared (FLIR) images is an important subject for aerospace and sensor surveillance. This paper presents a scheme to achieve a natural color image based on the contours feature of SAR and the target region feature of FLIR so that the overall scene recognitioFusion of synthetic aperture radar (SAR) and forward looking infrared (FLIR) images is an important subject for aerospace and sensor surveillance. This paper presents a scheme to achieve a natural color image based on the contours feature of SAR and the target region feature of FLIR so that the overall scene recognition and situational awareness can be improved. The SAR and FLIR images are first decomposed into steerable pyramids, and the contour maps in the SAR image and the region maps in the FLIR image are calculated. The contour and region features are fused at each level of the steerable pyramids. A color image is then formed by transferring daytime color to the monochromic image by using the natural color transfer technique. Experimental results show that the proposed method is effective in providing a color fusion of SAR and FLIR images..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04202 (2005)
Integrated Optics
Improving linearity of position-sensitive detector using support vector machines
Meiying Ye
An intelligent method for improving position linearity of position-sensitive detector (PSD), based on support vector machines (SVMs), is developed. The SVM is established based on the structural risk minimization principle rather than minimizing the empirical error commonly implemented in neural networks. SVM can achieAn intelligent method for improving position linearity of position-sensitive detector (PSD), based on support vector machines (SVMs), is developed. The SVM is established based on the structural risk minimization principle rather than minimizing the empirical error commonly implemented in neural networks. SVM can achieve higher generalization performance. Training SVM is equivalent to solving a linearly constrained quadratic programming problem, thus the solution of SVM is always unique and globally optimal. The improving position linearity procedure has been illustrated using a two-dimensional (2D) PSD. It is pointed out that the position linearity of the measuring system with a proper SVM correction is improved by two orders of magnitude in the measurement range..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04205 (2005)
Lasers and Laser Optics
High power all-solid-state quasi-continuous-wave tunable Ti:sapphire laser system
Lei Zou, Xin Ding, Yue Zou, Hongmei Ma, Wuqi Wen, Peng Wang, and Jianquan Yao
This paper reports a high power, all-solid-state, quasi-continuous-wave tunable Ti:sapphire laser system pumped by laser diode (LD) pumped frequency-doubled Nd:YAG laser. The maximum tuned output power of 4.2 W (797 nm) and tuned average power of 3.7 W were achieved when fixing the Ti:sapphire broadband output power atThis paper reports a high power, all-solid-state, quasi-continuous-wave tunable Ti:sapphire laser system pumped by laser diode (LD) pumped frequency-doubled Nd:YAG laser. The maximum tuned output power of 4.2 W (797 nm) and tuned average power of 3.7 W were achieved when fixing the Ti:sapphire broadband output power at 5.0 W and applying 750-850 nm broadband coated mirror..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04208 (2005)
3.6-W cryogenic Tm,Ho:YLF laser pumped by fiber-coupled diodes module
Baoquan Yao, Youlun Ju, Yuezhu Wang, Wanjun He, and Yufeng Li
In this paper, we report a high power cryogenic cooling Tm(6 at.-%),Ho(0.5 at.-%):YLF laser end-pumped by a 19-fiber-coupled-diodes module with the central wavelength of 792 nm at 20 deg.. The highest continuous-wave power of 3.6 W at 2.051 μm is attained under pumping power of 13.6 W, corresponding to optical-optical In this paper, we report a high power cryogenic cooling Tm(6 at.-%),Ho(0.5 at.-%):YLF laser end-pumped by a 19-fiber-coupled-diodes module with the central wavelength of 792 nm at 20 deg.. The highest continuous-wave power of 3.6 W at 2.051 μm is attained under pumping power of 13.6 W, corresponding to optical-optical conversion efficiency of 26%, and the slope efficiency is larger than 30%. The threshold power is only about 0.16 W because of the long lifetime, large effective emission cross section, and low re-absorption in Tm,Ho:YLF crystal..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04210 (2005)
Stable single frequency Er-doped all-fiber ring laser with fiber Bragg grating Fabry-Perot filter
Changgui Lv, Zhuyuan Wang, Binfeng Yun, and Yiping Cui
Using a fiber Bragg grating (FBG) and a Fabry-Perot cavity composed of two fiber Bragg gratings (FBGFP) as its frequency-selective components, a type of single frequency all-fiber ring laser permits oscillation only on one longitudinal mode of the main cavity without modehopping while the cavity length can be up to tenUsing a fiber Bragg grating (FBG) and a Fabry-Perot cavity composed of two fiber Bragg gratings (FBGFP) as its frequency-selective components, a type of single frequency all-fiber ring laser permits oscillation only on one longitudinal mode of the main cavity without modehopping while the cavity length can be up to tens of meters. The salient feature is due to the single narrowband resonance of the FBGFP filter. Such a fiber ring laser is achieved experimentally, and the laser mode is limited inside the single resonance of the FBGFP..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04212 (2005)
The intensity distribution and thermal stability of InnoSlab laser
Ning Wang, Peng Shi, and Yutian Lu
Partially end-pumped slab laser is an innovative solid state laser, namely InnoSlab. Combining the hybrid resonator with partially end-pumping, the output power can be scaled with high beam quality. In this paper, the output intensity distributions are simulated by coordinate transformation fast Fourier transform (FFT)Partially end-pumped slab laser is an innovative solid state laser, namely InnoSlab. Combining the hybrid resonator with partially end-pumping, the output power can be scaled with high beam quality. In this paper, the output intensity distributions are simulated by coordinate transformation fast Fourier transform (FFT) algorithm, comparing the thermal lens influence. As the simulated curves showed, the output mode is still good when the thermal lens effect is strong, indicating the good thermal stability of InnoSlab laser. Such a new kind of laser can be designed and optimized on the base of this simulation..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04215 (2005)
Materials
Raman spectra of undoped and uranium doped CaF2 single crystals
Liangbi Su, Jun Xu, Weiqiao Yang, Xiongwei Jiang, and Yongjun Dong
Raman scattering experiments for nominally pure and uranium doped CaF2 single crystals were presented. In all crystals, the Raman active T_(2g) vibration mode of CaF2 was observed, whose frequency shift and full-width at half-maximum (FWHM) broadening correspond well with defects and impurities in CaF2 lattice. AdditioRaman scattering experiments for nominally pure and uranium doped CaF2 single crystals were presented. In all crystals, the Raman active T_(2g) vibration mode of CaF2 was observed, whose frequency shift and full-width at half-maximum (FWHM) broadening correspond well with defects and impurities in CaF2 lattice. Additional Raman peaks develop in nominally pure CaF2 with high etch pits density and U^(6+):CaF2 crystals. Part of additional Raman peaks in the experimental results, which are assumed due to vibration modes from F- interstitials and vacancies, are in well agreement with the theoretical predications by employing the Green-function formulation..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04219 (2005)
The influence of OH groups on laser performance in phosphate glasses
Shunguang Li, Guosong Huang, Lei Wen, and Gangfeng Yang
Because of the influence of OH groups in phosphate glasses on the radiation of rare-earth ions, the laser performance is degraded. The laser efficiency and the small signal gain experiment of several phosphate glass samples have been done, the concentration of OH groups in glasses was calculated from the measured absorBecause of the influence of OH groups in phosphate glasses on the radiation of rare-earth ions, the laser performance is degraded. The laser efficiency and the small signal gain experiment of several phosphate glass samples have been done, the concentration of OH groups in glasses was calculated from the measured absorption coefficient at 3.47 μm. It is shown that the concentration of OH groups in phosphate glasses can seriously influence the laser output characteristics, and the OH groups have worse influence on the laser amplifier than laser oscillator..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04222 (2005)
Medical Optics and Biotechnology
High resolution mosaic image of capillaries in human retina by adaptive optics
Ning Ling, Yudong Zhang, Xuejun Rao, Cheng Wang, Yiyun Hu, and Wenhan Jiang
Adaptive optics (AO) has been proved as a powerful means for high resolution imaging of human retina. Because of the pixel number of charge-coupled device (CCD) camera, the field of view is limited to 1 deg.. In order to have image of capillaries around vivo human fovea, we use mosaic method to obtain high resolution iAdaptive optics (AO) has been proved as a powerful means for high resolution imaging of human retina. Because of the pixel number of charge-coupled device (CCD) camera, the field of view is limited to 1 deg.. In order to have image of capillaries around vivo human fovea, we use mosaic method to obtain high resolution image in area of 6deg.*6deg.. Detailed structures of capillaries around fovea with resolution of 2.3 μm are clearly shown. Comparison shows that this method has a much higher resolution than current clinic retina imaging methods..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04225 (2005)
Nonlinear Optics
Discrete elliptic solitons in two-dimensional waveguide arrays
Fangwei Ye, Liangwei Dong, Jiandong Wang, Tian Cai, and Yong-Ping Li
The fundamental properties of discrete elliptic solitons (DESs) in the two-dimensional waveguide arrays were studied. The DESs show nontrivial spatial structures in their parameters space due to the introduction of the new freedom of ellipticity, and their stability is closely linked to their propagation directions in The fundamental properties of discrete elliptic solitons (DESs) in the two-dimensional waveguide arrays were studied. The DESs show nontrivial spatial structures in their parameters space due to the introduction of the new freedom of ellipticity, and their stability is closely linked to their propagation directions in the transverse plane..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04227 (2005)
Fifth-order attosecond polarization beats using twin color-locked noisy lights in cascade three-level system with Doppler-free approach
Jianping Song, Yu Feng, Chenli Gan, Long Li, Yuanyuan Li, Xiaojun Yu, Hao Ge, Ruiqiong Ma, Chuangshe Li, Xiangchen Zhang, Yanpeng Zhang, and Keqing Lu
Fifth-order attosecond sum-frequency polarization beat (FASPB) is studied in a cascade three level system with the phase-conjugation fourth-order coherence function theory. An improved schematic diagram of geometry, which is different from that inducing fifth-order femtosecond different-frequency polarization beat (FFDFifth-order attosecond sum-frequency polarization beat (FASPB) is studied in a cascade three level system with the phase-conjugation fourth-order coherence function theory. An improved schematic diagram of geometry, which is different from that inducing fifth-order femtosecond different-frequency polarization beat (FFDPB), is used to obtain FASPB. By analyzing the cases that pump beams have either narrow or broad bandwidth, it is found that the temporal behavior of the sum-frequency polarization beat signal depends on the properties of the lasers and transverse relaxation rate of the atomic energy-level system. Finally, the cascaded four-wave mixing (FWM) processes and the difference between attosecond and femtosecond polarization beats have been discussed, it is found that cascaded or sequential lower processes can often obscure the direct fifth-order polarization beat processes..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04230 (2005)
Optical Devices
Investigation of switching-window in a gain-transparent UNI configuration
Lijun Li, Ming Chen, and Ge Fan
Switching-window in an interferometric configuration of a gain-transparent ultrafast nonlinear interferometer (gt-UNI) is investigated numerically. The phase change is observed in detail. To assess the performance of switching window, the integrated contrast ratio (ICR) is introduced. For the data pulse with the bit wiSwitching-window in an interferometric configuration of a gain-transparent ultrafast nonlinear interferometer (gt-UNI) is investigated numerically. The phase change is observed in detail. To assess the performance of switching window, the integrated contrast ratio (ICR) is introduced. For the data pulse with the bit width of 6.25 ps and with the energy of 60 pJ, respectively, the ICRs in different situations are simulated using modified nonlinear Schrodinger equation (MNLSE) considering of the carrier depletion pulsation (CDP), carrier heating (CH), and spectral-hole burning (SHB). The results show that the maximum ICR is located at the optimum position of the semiconductor optical amplifier (SOA) that is determined by the width and energy of the control pulse..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04237 (2005)
Thin Films
Design of anisotropic reflector with birefringent thin films
Jianguo Wang, Kui Yi, Jianda Shao, and Zhengxiu Fan
A novel design for dielectric anisotropic mirrors with birefringent thin films for normal incidence is presented. This mirror consists of a stack of quarter-wave biaxial layers. The biaxial anisotropic layers can be fabricated by oblique deposition. The reflectance is different for two linear polarizations of light incA novel design for dielectric anisotropic mirrors with birefringent thin films for normal incidence is presented. This mirror consists of a stack of quarter-wave biaxial layers. The biaxial anisotropic layers can be fabricated by oblique deposition. The reflectance is different for two linear polarizations of light incidence on the mirrors. As a numerical example, the design is carried out on glass with TiO2 and ZrO2. These thin films could be applied to anisotropic reflective devices for lasers..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04247 (2005)
Quantum Optics
Constructing a universal set of quantum gates via probabilistic teleportation
Libing Chen, Hong Lu, and Weicheng Chen
We present a general method to construct a universal set of quantum gates using probabilistic teleportation as a basic primitive. The technique generalizes the teleportation method of gate construction to partially entangled quantum channels. Without recourse to local filtering or entanglement concentration, using locaWe present a general method to construct a universal set of quantum gates using probabilistic teleportation as a basic primitive. The technique generalizes the teleportation method of gate construction to partially entangled quantum channels. Without recourse to local filtering or entanglement concentration, using local rotation and CNOT operations followed by measurements in the computational basis, one can construct many encoded quantum operations with unit fidelity but less than unit probability. The technique can also be applied to the construction of remote quantum gates that cannot be directly performed..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04240 (2005)
Optical Computing
All-optical multibit address recognition at 20 Gb/s based on TOAD
Yumei Yan, Jian Wu, and Jintong Lin
All-optical multibit address recognition at 20 Gb/s is demonstrated based on a special AND logic of terahertz optical asymmetric demultiplexer (TOAD). The semiconductor optical amplifier (SOA) used in the TOAD is biased at transparency status to accelerate the gain recovery. This is the highest bit rate that multibit aAll-optical multibit address recognition at 20 Gb/s is demonstrated based on a special AND logic of terahertz optical asymmetric demultiplexer (TOAD). The semiconductor optical amplifier (SOA) used in the TOAD is biased at transparency status to accelerate the gain recovery. This is the highest bit rate that multibit address recognition is demonstrated with SOA-based interferometer. The experimental results show low pattern dependency. With this method, address recognition can be performed without separating address and payload beforehand..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 3, Issue 4, 04234 (2005)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20