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Editorial for focus issue on microwave photonics
José Capmany, Jianping Yao, Wei Li, and Pan Shilong
Microwave photonic components and subsystems can replace or complement their electronic counterparts with a net gain in functionality, bandwidth, size, mass, complexity, and cost, facilitating the innovative implementation of radio frequency (RF) systems due to broad bandwidth, low loss, light weight, flat frequency response, favorable isolation, and immunity to electromagnetic interference (EMI) provided by photonic technologies. Much attention has been recently paid to this area, which results in impressive progresses. Hence, we designed a focus issue intended to introduce the recent advancements in this field, especially the works by some distinguished research groups. Microwave photonic components and subsystems can replace or complement their electronic counterparts with a net gain in functionality, bandwidth, size, mass, complexity, and cost, facilitating the innovative implementation of radio frequency (RF) systems due to broad bandwidth, low loss, light weight, flat frequency response, favorable isolation, and immunity to electromagnetic interference (EMI) provided by photonic technologies. Much attention has been recently paid to this area, which results in impressive progresses. Hence, we designed a focus issue intended to introduce the recent advancements in this field, especially the works by some distinguished research groups.
Chinese Optics Letters
- Publication Date: Jan. 10, 2017
- Vol. 15, Issue 1, 010001 (2017)
Novel orthogonal modulation format DRZ-FSK/DPSK for high-speed long-haul optical communication
Junwen Zhang, Yufeng Shao, Wuliang Fang, Bo Huang, Li Tao, Jiangbo Zhu, and Nan Chi
We propose a novel advanced orthogonal modulation format dark return-to-zero frequency shift keying/differential phase shift keying (DRZ-FSK/DPSK) and its realization scheme. The DRZ-FSK/DPSK is generated by the combination of a 40-Gb/s return-to-zero (RZ) signal and a DRZ signal which is converted from the RZ using a semiconductor optical amplifier (SOA) based on nonlinear cross polarization rotation (XPR) and then re-modulated by high-bit-rate DPSK at 40 Gb/s. The feasibility of the scheme is experimentally demonstrated. Bit error rate (BER) results of the total 80-Gb/s DRZ-FSK/DPSK orthogonal modulation signal with a subsequent 100-km single-mode fiber (SMF) transmission link show its potential for future high-speed long-haul optical communication. We propose a novel advanced orthogonal modulation format dark return-to-zero frequency shift keying/differential phase shift keying (DRZ-FSK/DPSK) and its realization scheme. The DRZ-FSK/DPSK is generated by the combination of a 40-Gb/s return-to-zero (RZ) signal and a DRZ signal which is converted from the RZ using a semiconductor optical amplifier (SOA) based on nonlinear cross polarization rotation (XPR) and then re-modulated by high-bit-rate DPSK at 40 Gb/s. The feasibility of the scheme is experimentally demonstrated. Bit error rate (BER) results of the total 80-Gb/s DRZ-FSK/DPSK orthogonal modulation signal with a subsequent 100-km single-mode fiber (SMF) transmission link show its potential for future high-speed long-haul optical communication.
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 8, Issue 9, 852 (2010)
Editorial for Focus Issue on Enabling Science and Technology for High-Speed Optical Communications
Tingye Li, Zisen Zhao, and Jianjun Yu
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 8, Issue 9, 815 (2010)
Measurement of third-order nonlinear optical susceptibility of synthetic diamonds
Jianxun Zhao, Gang Jia, Xiuhuan Liu, Zhanguo Chen, Jie Tang, and Shuang Wang
Diamonds are wide-gap semiconductors possessing excellent physical and chemical properties; thus, they are regarded as very appropriate materials for optoelectronic devices. Based on the Kerr effect, we introduce a simple and feasible method for measuring the third-order nonlinear optical susceptibility of synthetic diamonds. In the experiments, synthetic type I diamond samples and transverse electro-optic modulation systems are utilized. As for the laser with the wavelength of 650 nm, the third-order susceptibility and Kerr coefficient of the diamond samples are obtained at χ<sup>(3)</sup><sub>1212</sub>=2:17×10<sup>-23</sup> m<sup>2</sup>=V<sup>2</sup> and S<sub>44</sub>= 1.93×10<sup>-23</sup> m<sup>2</sup>=V<sup>2</sup>, respectively. Diamonds are wide-gap semiconductors possessing excellent physical and chemical properties; thus, they are regarded as very appropriate materials for optoelectronic devices. Based on the Kerr effect, we introduce a simple and feasible method for measuring the third-order nonlinear optical susceptibility of synthetic diamonds. In the experiments, synthetic type I diamond samples and transverse electro-optic modulation systems are utilized. As for the laser with the wavelength of 650 nm, the third-order susceptibility and Kerr coefficient of the diamond samples are obtained at χ<sup>(3)</sup><sub>1212</sub>=2:17×10<sup>-23</sup> m<sup>2</sup>=V<sup>2</sup> and S<sub>44</sub>= 1.93×10<sup>-23</sup> m<sup>2</sup>=V<sup>2</sup>, respectively.
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 8, Issue 7, 685 (2010)
High-resolution photoacoustic microscope for rat brain imaging in vivo
Xiaoquan Yang, Xin Cai, Konstantin Maslov, Lihong Wang, and Qingming Luo
A reflection-mode photoacoustic microscope (PAM) for rat brain imaging in vivo is constructed. A pulsed laser is used as an excitation source, and a focused ultrasound transducer is adopted to collect the photoacoustic signal. Raster scanning is applied to acquire three-dimensional (3D) data. The obtained measurements of the lateral and axial resolutions of the microscope are 45 and 15 \mu m, respectively. The imaging depth in the chicken breast tissue is 3.1 mm at a signal-to-noise ratio (SNR) of 20 dB without any signal averaging. The imaging speed is 30 A-line/s. Experimental results in vivo demonstrate the capability of 3D imaging of the brain vessels of the rat after removing the skull. A reflection-mode photoacoustic microscope (PAM) for rat brain imaging in vivo is constructed. A pulsed laser is used as an excitation source, and a focused ultrasound transducer is adopted to collect the photoacoustic signal. Raster scanning is applied to acquire three-dimensional (3D) data. The obtained measurements of the lateral and axial resolutions of the microscope are 45 and 15 \mu m, respectively. The imaging depth in the chicken breast tissue is 3.1 mm at a signal-to-noise ratio (SNR) of 20 dB without any signal averaging. The imaging speed is 30 A-line/s. Experimental results in vivo demonstrate the capability of 3D imaging of the brain vessels of the rat after removing the skull.
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 8, Issue 6, 609 (2010)
Fabrication of a novel silica PLC hybrid integrated triplexer
Junyi Li, Junming An, Yuanda Wu, Jianguang Li, Hongjie Wang, and Xiongwei Hu
A new-style silica planar lightwave circuit (PLC) hybrid integrated triplexer, which can demultiplex 1490-nm download data and 1550-nm download analog signals, as well as transmit 1310-nm upload data, is presented. It combines SiO2 arrayed waveguide gratings (AWGs) with integrated photodetectors (PDs) and a high performance laser diode (LD). The SiO2 AWGs realize the three-wavelength coarse wavelength division multiplexing (CWDM). The crosstalk is less than -40 dB between the 1490- and 1550-nm channels, and less than -45 dB between 1310- and 1490- or 1550-nm channels. For the static performances of the integrated triplexer, its upload output power is 0.4 mW, and the download output photo-generated current is 76 \mu A. In the small-signal measurement, the upstream -3-dB bandwidth of the triplexer is 4 GHz, while the downstream -3-dB bandwidths of both the analog and digital sections reach 1.9 GHz. A new-style silica planar lightwave circuit (PLC) hybrid integrated triplexer, which can demultiplex 1490-nm download data and 1550-nm download analog signals, as well as transmit 1310-nm upload data, is presented. It combines SiO2 arrayed waveguide gratings (AWGs) with integrated photodetectors (PDs) and a high performance laser diode (LD). The SiO2 AWGs realize the three-wavelength coarse wavelength division multiplexing (CWDM). The crosstalk is less than -40 dB between the 1490- and 1550-nm channels, and less than -45 dB between 1310- and 1490- or 1550-nm channels. For the static performances of the integrated triplexer, its upload output power is 0.4 mW, and the download output photo-generated current is 76 \mu A. In the small-signal measurement, the upstream -3-dB bandwidth of the triplexer is 4 GHz, while the downstream -3-dB bandwidths of both the analog and digital sections reach 1.9 GHz.
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 8, Issue 6, 588 (2010)
Modeling light propagation through taper-microfiber structures integrated on substrates
Xufeng Kou, Guillaume Vienne, and Guanghui Wang
We use the three-dimensional finite-difference time-domain (3D-FDTD) method to model silica tapermicrofiber structures integrated on substrates. The dependence of the transmission on the length of the microfiber is investigated for two different structures. Optimization of the geometric parameters is provided and two substrate materials, namely MgF2 and fluorosilicate glass, are considered. We also investigate the case where the structure is covered with a dielectric material. We use the three-dimensional finite-difference time-domain (3D-FDTD) method to model silica tapermicrofiber structures integrated on substrates. The dependence of the transmission on the length of the microfiber is investigated for two different structures. Optimization of the geometric parameters is provided and two substrate materials, namely MgF2 and fluorosilicate glass, are considered. We also investigate the case where the structure is covered with a dielectric material.
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 8, Issue 6, 560 (2010)
Study on interaction between Dy(III)(NR)3 complex and herring sperm DNA by spectroscopy
Yan Zhang, Xingming Wang, Dan Fei, Na Zhao, Tingting Zhao, Haifeng Zhu, and Lisheng Ding
The action mode between Dy(III)(NR)<sub>3</sub> and herring sperm DNA is studied by ultraviolet-visible (UV-vis) and fluorescence spectra as well as electrochemistry. Double-reciprocal method studies show that the binding stoichiometry between Dy(III)(NR)<sub>3</sub> and DNA is 1:1, the binding constants at different temperatures are 1。15×10<sup>5</sup> L/mol at 25 ℃ and 2.09×10<sup>5</sup> L/mol at 35 ℃, and the corresponding thermodynamic parameters are \Delta<sub>r</sub>H \mathrm m = 2.48×10<sup>4</sup> J/mol, \Delta<sub>r</sub>G \mathrm m =-2.34×10<sup>4</sup> J/mol, \Delta<sub>r</sub>Sm=161.7 J/(mol·K); \Delta<sub>r</sub>S \mathrm m is the driving force in this reaction. Combined with Scatchard method and melting method, the results suggest that the interaction mode between Dy(III)(NR)<sub>3</sub> and herring sperm DNA is intercalation fashion and groove fashion. The action mode between Dy(III)(NR)<sub>3</sub> and herring sperm DNA is studied by ultraviolet-visible (UV-vis) and fluorescence spectra as well as electrochemistry. Double-reciprocal method studies show that the binding stoichiometry between Dy(III)(NR)<sub>3</sub> and DNA is 1:1, the binding constants at different temperatures are 1。15×10<sup>5</sup> L/mol at 25 ℃ and 2.09×10<sup>5</sup> L/mol at 35 ℃, and the corresponding thermodynamic parameters are \Delta<sub>r</sub>H \mathrm m = 2.48×10<sup>4</sup> J/mol, \Delta<sub>r</sub>G \mathrm m =-2.34×10<sup>4</sup> J/mol, \Delta<sub>r</sub>Sm=161.7 J/(mol·K); \Delta<sub>r</sub>S \mathrm m is the driving force in this reaction. Combined with Scatchard method and melting method, the results suggest that the interaction mode between Dy(III)(NR)<sub>3</sub> and herring sperm DNA is intercalation fashion and groove fashion.
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 8, Issue 2, 236 (2010)
Effective medium theory applied to frequency selective surfaces on periodic substrates
Huaxin Zhu, Jinsong Gao, Jingli Zhao, Tongtong Wang, Xiaoguo Feng, Fengchao Liang, Yansong Wang, and Xin Chen
We apply the effective medium theory combined with the conventional periodic method of moments (MoM) to analyze frequency selective surfaces (FSSs) on periodic and anisotropic substrates. Based on the effective medium theory, even periodic and anisotropic substrates can be considered homogeneous; thus, the Green's function can be obtained. The resulting integral equation can then be solved by the MoM using rooftop basis functions and Galerkin testing functions. We analyze an example using this technique, and the numerical results agree with Fallahi's full-vector semi-analytical method, showing an increasing difference between the results as the frequencies increase. These results show that the proposed method is effective for analyzing FSSs on periodic and anisotropic substrates. We apply the effective medium theory combined with the conventional periodic method of moments (MoM) to analyze frequency selective surfaces (FSSs) on periodic and anisotropic substrates. Based on the effective medium theory, even periodic and anisotropic substrates can be considered homogeneous; thus, the Green's function can be obtained. The resulting integral equation can then be solved by the MoM using rooftop basis functions and Galerkin testing functions. We analyze an example using this technique, and the numerical results agree with Fallahi's full-vector semi-analytical method, showing an increasing difference between the results as the frequencies increase. These results show that the proposed method is effective for analyzing FSSs on periodic and anisotropic substrates.
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 8, Issue 12, 1175 (2010)
In-vivo fluorescence molecular tomography based on optimal small animal surface reconstruction
Daifa Wang, Xin Liu, Yanping Chen, and Jing Bai
Accurate small animal surface reconstruction is important for full angle non-contact fluorescence molecular tomography (FMT) systems. In this letter, an optimal surface reconstruction method for FMT is proposed. The proposed method uses a line search method to minimize the mismatch between the reconstructed three-dimensional (3D) surface and the projected object silhouette at different angles. The results show that the mean mismatches of the 3D surfaces generated on three live anesthetized mice are all less than two charge coupled device (CCD) pixels (0.154 mm). With the accurately reconstructed 3D surface, in-vivo FMT is also performed. Accurate small animal surface reconstruction is important for full angle non-contact fluorescence molecular tomography (FMT) systems. In this letter, an optimal surface reconstruction method for FMT is proposed. The proposed method uses a line search method to minimize the mismatch between the reconstructed three-dimensional (3D) surface and the projected object silhouette at different angles. The results show that the mean mismatches of the 3D surfaces generated on three live anesthetized mice are all less than two charge coupled device (CCD) pixels (0.154 mm). With the accurately reconstructed 3D surface, in-vivo FMT is also performed.
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 8, Issue 1, 82 (2010)
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