Journals >Optoelectronics Letters
Contents
2014
Volume: 10 Issue 6
20 Article(s)
Export citation format
Research Article
A variable coefficient microwave photonic filter based on multi-wavelength fiber laser and Mach-Zehnder interferometer
Ye CAO, Ce LIU, and Zheng-rong TONG
A microwave photonic filter (MPF) with variable coefficient is proposed and demonstrated, which is constructed by a multi-wavelength fiber laser and Mach-Zehnder interferometer (MZI). Through changing the slope characteristics of Mach-Zehnder interference spectrum adjusted by optical variable delay line (OVDL), the conA microwave photonic filter (MPF) with variable coefficient is proposed and demonstrated, which is constructed by a multi-wavelength fiber laser and Mach-Zehnder interferometer (MZI). Through changing the slope characteristics of Mach-Zehnder interference spectrum adjusted by optical variable delay line (OVDL), the conversion from phase modulation (PM) to intensity modulation (IM) is realized. The multi-wavelength fiber laser with Lyot-Sagnac optical filter has variable wavelength spacing. So the designed filter has a variable number of taps and tap weights. As a result, the tunable range of passband center frequency is 2.6 GHz. The reconfigurability of MPF can be also realized by adjusting the output of fiber laser..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 401 (2014)
A flexible receiver with fiber optical parametric amplifier in OCDMA-FSO communication system
Min XIA, Jin-hui YUAN, Xin-zhu SANG, Xiao-li YIN, Lan RAO, and Chong-xiu YU
A new receiver is proposed, which uses the fiber optical parametric amplifier (FOPA) in optical code division multiple access (OCDMA) over free space optic (FSO) communication system. The noise tolerance as the performance index in this receiver is derived. The receiver can not only improve the noise tolerance but alsoA new receiver is proposed, which uses the fiber optical parametric amplifier (FOPA) in optical code division multiple access (OCDMA) over free space optic (FSO) communication system. The noise tolerance as the performance index in this receiver is derived. The receiver can not only improve the noise tolerance but also change the pump data conveniently for adapting to the length variation of the coding sequence under a complex and fast-changing weather condition. The influence of different factors on the noise tolerance is analyzed, and a significant improvement of about 18.77 dB for the noise tolerance can be achieved when the pump power and the length of coding sequence are 5 W and 256, respectively..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 406 (2014)
Novel metal-dielectric metameric optical filters for optical security devices
Rong GUO, Nan CHEN, Lu-jian CHEN, Xiao-zhong WANG, Zhi-ping CAI, Yan-kai LI, and Yi-kun BU
Optical security devices play an essential role in the fight against counterfeiting. In this paper, we study and design a pair of metal-dielectric optical filters based on metameric effect, which offer a hidden image effect by the color shift at a specific angle of observation. Compared with all-dielectric multilayer sOptical security devices play an essential role in the fight against counterfeiting. In this paper, we study and design a pair of metal-dielectric optical filters based on metameric effect, which offer a hidden image effect by the color shift at a specific angle of observation. Compared with all-dielectric multilayer system, the metal-dielectric multilayer structure has larger color shift with varying incident angle, higher color saturation and fewer layers. Finally, the stacks with 5 layers and 7 layers are achieved, and the color difference index is only 0.71, which shows good metameric matching effect. Simultaneously, the sensitivity of filters to deposition errors is analyzed when the thickness deviation is ±2%, and the results show that the two filters have good manufacturability..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 411 (2014)
Design of XOR/XNOR optical logic circuit with two cascaded microring resonators and U-bend waveguides
Xin ZHANG, Zhi-quan LI, and Kai TONG
An XOR/XNOR optical logic circuit with two cascaded microring resonators and two U-bend waveguides is proposed. The microring resonators are made of electro-optical polymer and modulated through linear electro-optical effect. Two electrical signals are applied to the two microrings, and simultaneous XOR and XNOR operatAn XOR/XNOR optical logic circuit with two cascaded microring resonators and two U-bend waveguides is proposed. The microring resonators are made of electro-optical polymer and modulated through linear electro-optical effect. Two electrical signals are applied to the two microrings, and simultaneous XOR and XNOR operations are demonstrated in two different operating modes. We also use scattering matrix method to analyze the analog output spectra, and find that different inputs like ‘00’ and ‘11’ can lead to different extinction ratios in output spectra at certain wavelengths, even though their digital outputs are the same..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 415 (2014)
Simplification of integral imaging system by using a lenticular lens array
Lei ZHANG, and Xiao-xue JIAO
Integral imaging is a 3D display technology without any additional equipment. A new system is proposed in this paper, which uses a lenticular lens array to replace the lens array in the conventional integral imaging system. The lenticular integral imaging system reduces the complexity and the price of integral imaging Integral imaging is a 3D display technology without any additional equipment. A new system is proposed in this paper, which uses a lenticular lens array to replace the lens array in the conventional integral imaging system. The lenticular integral imaging system reduces the complexity and the price of integral imaging system. The positive characteristics of conventional integral imaging system, such as full parallax and quasi-continuous view points, are still kept on the proposed system in horizontal direction. Optical results show that the time for calculating the elemental images is reduced by 25% compared with the conventional one. The resolution of integrated image in vertical direction is 4 times higher than that of conventional system. This proposed system opens a new way on application of integral imaging..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 420 (2014)
C-cut Nd-doped vanadate crystal self-Raman laser with narrow Q-switched envelope and high mode-locked repetition rate
Zuo-han LI, Ji-ying PENG, Yi ZHENG, Ye YANG, and Jin-hua KOU
In this paper, a passively Q-switched and mode-locked c-cut Nd-doped vanadate crystal self-Raman laser at 1.17 μm is firstly demonstrated by using Cr4+:YAG. Two crystals of Nd3+:YVO4and Nd3+:GdVO4are adopted to generate laser, respectively. With the incident pump power of 13 W, the average output powers of 678 mW and 8In this paper, a passively Q-switched and mode-locked c-cut Nd-doped vanadate crystal self-Raman laser at 1.17 μm is firstly demonstrated by using Cr4+:YAG. Two crystals of Nd3+:YVO4and Nd3+:GdVO4are adopted to generate laser, respectively. With the incident pump power of 13 W, the average output powers of 678 mW and 852 mW at 1.17 μm are obtained with the durations of Q-switched envelope of 1.8 ns and 2 ns, respectively. The mode-locked repetition rates are as high as 2.3 Hz and 2.2 GHz, respectively. As far as we know, the Q-switched envelope is the narrowest and the mode-locked repetition rate is the highest at present in this field. In addition, yellow laser output is also achieved by using the LiB3O5frequency doubling crystal..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 423 (2014)
Dual-wavelength erbium-doped fiber laser with asymmetric fiber Bragg grating Fabry-Perot cavity
Cong CHEN, Zhi-wei XU, Meng WANG, and Hai-yan CHEN
A novel dual-wavelength fiber laser with asymmetric fiber Bragg grating (FBG) Fabry-Perot (FP) cavity is proposed and experimentally demonstrated. A couple of uniform FBGs are used as the cavity mirrors, and the third FBG is used as intracavity wavelength selector by changing its operation temperature. Experimental resA novel dual-wavelength fiber laser with asymmetric fiber Bragg grating (FBG) Fabry-Perot (FP) cavity is proposed and experimentally demonstrated. A couple of uniform FBGs are used as the cavity mirrors, and the third FBG is used as intracavity wavelength selector by changing its operation temperature. Experimental results show that by adjusting the operation temperature of the intracavity wavelength selector, a tunable dual-wavelength laser emission can be achieved. The results demonstrate the new concept of dual-wavelength lasing with asymmetric FBG FP resonator and its technical feasibility..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 427 (2014)
A high performance all-optical set-reset flip-flop based on SOA-MZI
Sohrabtash Jahanshir, Zarifkar Abbas, and Sheikhi Mohammad Hossein
A set-reset all-optical flip-flop (SR-AOFF) based on semiconductor optical amplifier Mach-Zehnder interferometer (SOA-MZI) is proposed. Simulation results show that low switching energy in the femto joule range, the transition time of less than 20 ps, high stability and high extinction ratio (ER) of 30 dB can be achievA set-reset all-optical flip-flop (SR-AOFF) based on semiconductor optical amplifier Mach-Zehnder interferometer (SOA-MZI) is proposed. Simulation results show that low switching energy in the femto joule range, the transition time of less than 20 ps, high stability and high extinction ratio (ER) of 30 dB can be achieved, while AOFF output is power insensitive approximately..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 430 (2014)
A switchable dual-wavelength erbium-doped fiber lasebased on saturable absorber and active optical fiber ring filter
Lian-qing ZHU, Qing-shan CHEN, Ran-ran ZHAO, Xiao-ping LOU, and Wei HE
A dual-wavelength erbium-doped fiber laser (EDFL) with outstanding stability is presented. In the fiber laser system, two nested active optical fiber ring filters are configured to improve the comb spectrum performance, a saturable absorber is employed to form a gain grating for both filtering and frequency stabilizingA dual-wavelength erbium-doped fiber laser (EDFL) with outstanding stability is presented. In the fiber laser system, two nested active optical fiber ring filters are configured to improve the comb spectrum performance, a saturable absorber is employed to form a gain grating for both filtering and frequency stabilizing, two cascaded fiber Bragg gratings (FBGs) are utilized to achieve dual-wavelength output, and a variable attenuator is arranged to adjust output power. Experimental results illustrate that the peak wavelength drift is less than 3 pm, and a good linear relationship between output power and pump power is realized..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 434 (2014)
Gaussian beam shaping based on aspheric cylindrical lenses
Guang-yuan SHI, Song LI, Ke HUANG, Hong YI, and Jin-ling YANG
We propose a specific aspheric cylindrical optical system to transform Gaussian beam to flat-top and rectangular beam. The Gaussian beam shaping system is composed of dual orthogonal aspheric cylindrical lenses. The principle of shaping Gaussian beam is studied theoretically. The mapping function of arbitrary rays in aWe propose a specific aspheric cylindrical optical system to transform Gaussian beam to flat-top and rectangular beam. The Gaussian beam shaping system is composed of dual orthogonal aspheric cylindrical lenses. The principle of shaping Gaussian beam is studied theoretically. The mapping function of arbitrary rays in an incident plane and an image plane is deduced based on the law of energy conservation, and the real ray tracing method is adopted to design the shaping system. Finally, the lens system is processed by single point diamond turning techniques. Testing results indicate that the system achieves the theoretical expectation, and the uniformity of flat-top and rectangular beam is 88.2%. The method is not only simple but also practical..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 439 (2014)
Luminescent properties of Tm3+/ Ho3+co-doped LiYF4crystals
Shan-shan LI, Hai-ping XIA, Yan-ming DONG, Li FU, Xue-mei GU, Jian-li ZHANG, Dong-jie WANG, Hao-chuan JIANG, and Bao-jiu CHEN
Ho3+with various concentrations and Tm3+with molar concentration of 1.28% are co-doped in LiYF4(YLF) single crystals. The luminescent properties of the crystals are investigated through emission spectra, emission cross section and decay curves under the excitation of 808 nm. The energy transfer from Tm3+to Ho3+and the Ho3+with various concentrations and Tm3+with molar concentration of 1.28% are co-doped in LiYF4(YLF) single crystals. The luminescent properties of the crystals are investigated through emission spectra, emission cross section and decay curves under the excitation of 808 nm. The energy transfer from Tm3+to Ho3+and the optimum fluorescence emission of Ho3+around 2.05 μm are investigated. The emission intensity at 2.05 μm keeps increasing with the molar concentration of Ho3+improved from 0.50% to 1.51% when the molar concentration of Tm3+ is kept at 1.28%. Moreover, for the co-doped crystals in which the molar concentrations of Tm3+and Ho3+are 1.28% and 1.51%, respectively, the maximum emission cross section reaches 0.760×10-20cm2and the maximum fluorescence lifetime is 21.98 ms. All the parameters suggest that these materials have more advantages in the future 2.0 μm laser applications..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 443 (2014)
Tunable emission, concentration quenching and crystallographic sites of Eu2+in Sr3Y(PO4)3
Zi-cai ZHANG, Shu-chao XU, Pan-lai LI, Zhi-jun WANG, Jiang SUN, Zhi-ping YANG, and Li-bin PANG
A series of Sr3Y(PO4)3:Eu2+samples are synthesized by the high temperature solid-state method. Sr3Y(PO4)3:Eu2+shows an asymmetrical emission band under excitation of 350 nm. The emission peaks at 426 nm and 497 nm are assigned to the nine-coordination Eu2+and six-coordination Eu2+, respectively. The effects of Eu2+ dopA series of Sr3Y(PO4)3:Eu2+samples are synthesized by the high temperature solid-state method. Sr3Y(PO4)3:Eu2+shows an asymmetrical emission band under excitation of 350 nm. The emission peaks at 426 nm and 497 nm are assigned to the nine-coordination Eu2+and six-coordination Eu2+, respectively. The effects of Eu2+ doping content on the emission intensity and color are observed, and the concentration quenching effect is also observed. For two different Eu2+luminescence centers, the quenching mechanisms are dipole-dipole interaction and quadrupole-quadrupole interaction, respectively. And the critical distance of energy transfer is calculated by concentration quenching and turns out to be about 3.67 nm. The results above show that the asymmetrical emission band of Sr3Y(PO4)3:Eu2+ comes from two different Eu2+2+ luminescence centers in the lattice..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 447 (2014)
Photoluminescence properties of solid-state Tb3+doped NaY(MoO4)2
Hai-yan LIU, Kun ZHANG, Li-bin PANG, Shao-jie GAO, Zhan-jun GAO, Ping-guang DUAN, Zi-cai ZHANG, and Zhi-jun WANG
A series of Tb3+doped NaY(MoO4)2are synthesized by a solid-state reaction at 550 °C for 4 h, and their luminescent properties are investigated. The phase formation is carried out with X-ray powder diffraction analysis, and there is no other crystalline phase except NaY(MoO4)2. NaY(MoO4)2:Tb3+can produce the green A series of Tb3+doped NaY(MoO4)2are synthesized by a solid-state reaction at 550 °C for 4 h, and their luminescent properties are investigated. The phase formation is carried out with X-ray powder diffraction analysis, and there is no other crystalline phase except NaY(MoO4)2. NaY(MoO4)2:Tb3+can produce the green emission under 290 nm radiation excitation, and the luminescence emission peak at 545 nm corresponds to the 5D4→7F5 transition of Tb3+. The emission intensity of Tb3+in NaY(MoO4)2is enhanced with the increase of Tb3+concentration, and there is no concentration quenching effect. The phenomena are proved by the decay curves of Tb3+. Moreover, the Commission International de I’Eclairage (CIE) chromaticity coordinates of NaY(MoO4)2:Tb3+locate in the green region..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 451 (2014)
A cost-effective ultra-dense WDM PON system with speed of 12.5 Gbit/s and channel spacing of 12.5 GHz
Hong-qian MU, Mu-guang WANG, and Shui-sheng JIAN
A cost-effective ultra-dense wavelength-division-multiplexed passive optical network (UD-WDM PON) with speed of 12.5 Gbit/s and channel spacing of 12.5 GHz is proposed and demonstrated. The distributed feedback (DFB) lasers modulated in 4-level pulse amplitude modulation (4-PAM) format are used for downstream links, anA cost-effective ultra-dense wavelength-division-multiplexed passive optical network (UD-WDM PON) with speed of 12.5 Gbit/s and channel spacing of 12.5 GHz is proposed and demonstrated. The distributed feedback (DFB) lasers modulated in 4-level pulse amplitude modulation (4-PAM) format are used for downstream links, and the reflective semiconductor optical amplifiers (RSOAs) together with an optical frequency comb modulated in quadrature phase shift keying (QPSK) format are used for upstream links. We can achieve the error-free transmission of the upstream signals with speed of 12.5 Gbit/s even after 20 km single-mode fiber (SMF). The power penalty obtained by using the frequency comb generator instead of a tunable laser is around 0.5 dB. By using 11 DFB lasers and a set of intensity and phase modulators, it is possible to provide the seed light for 297 optical network units (ONUs) within the C-band..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 455 (2014)
An experimental scheme for cordwood color division multiplexing VLC system
Jian-zhi DENG, and Xiao-hui CHENG
In this paper, an experimental scheme for cordwood color division multiplexing (CDM) visible light communication (VLC) system is proposed. The principle and structure of the experimental scheme are described. Right angle prisms and band-pass filter are used to make the unit of the optical collector and splitter. We canIn this paper, an experimental scheme for cordwood color division multiplexing (CDM) visible light communication (VLC) system is proposed. The principle and structure of the experimental scheme are described. Right angle prisms and band-pass filter are used to make the unit of the optical collector and splitter. We can add or subtract the unit as we need. The cordwood CDM-VLC system can also be effectively used as a model to accomplish color shift keying and color division duplexing. The experimental system provides a new way for researching VLC..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 459 (2014)
Supercontinuum generation at 1.55 μm in an all-normal dispersion photonic crystal fiber with high-repetition-rate picosecond pulses
Yong-zhao XU, Tao HAN, Jian-xun SONG, Dong-xiong LING, and Hong-tao LI
We demonstrate the generation of supercontinuum (SC) spectrum covering S+C+L band of optical communication by injecting 1.4 ps optical pulses with center wavelength of 1 552 nm and repetition rate of 10 GHz into an all-normal dispersion photonic crystal fiber (PCF) with length of 80 m. The experimental results are in gWe demonstrate the generation of supercontinuum (SC) spectrum covering S+C+L band of optical communication by injecting 1.4 ps optical pulses with center wavelength of 1 552 nm and repetition rate of 10 GHz into an all-normal dispersion photonic crystal fiber (PCF) with length of 80 m. The experimental results are in good agreement with the numerical simulations, which are used to illustrate the SC generation dynamics by self-phase modulation and optical wave breaking (WB)..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 463 (2014)
Photoacoustic Doppler flowmetry of carbon particles flow using an autocorrelation method
Tao LU
In order to measure the axial flowing velocity of carbon particle suspension with particle diameter of tens of micrometers, the photoacoustic Doppler (PAD) frequency shift is calculated based on a series of individual A scans using an autocorrelation method. A 532 nm pulsed laser with repetition rate of 20 Hz is used aIn order to measure the axial flowing velocity of carbon particle suspension with particle diameter of tens of micrometers, the photoacoustic Doppler (PAD) frequency shift is calculated based on a series of individual A scans using an autocorrelation method. A 532 nm pulsed laser with repetition rate of 20 Hz is used as a pumping source to generate photoacoustic signal. The photoacoustic signals are detected using a focused piezoelectric (PZT) ultrasound transducer with central frequency of 5 MHz. The suspension of carbon particles is driven by a syringe pump. The complex photoacoustic signal is calculated by the Hilbert transformation from time-domain photoacoustic signal, and then it is autocorrelated to calculate the Doppler frequency shift. The photoacoustic Doppler frequency shift is calculated by averaging the autocorrelation results of some individual A scans. The advantage of the autocorrelation method is that the time delay in autocorrelation can be defined by user, and the requirement of high pulse repetition rate is avoided. The feasibility of the proposed autocorrelation method is preliminarily demonstrated by quantifying the motion of a carbon particle suspension with flow velocity from 5 mm/s to 60 mm/s. The experimental results show that there is an approximately linear relation between the autocorrelation result and the setting velocity..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 467 (2014)
Measurement of the anisotropy factor with azimuthal light backscattering
Pin WANG, Yong-ming LI, and Bo-han CHEN
The potential capability of low coherence backscattering (LBS) is explored to determine the anisotropy factor based on azimuthal light backscattering map. The scattering intensity signal measured at azimuthal angle φ=0° is extracted for analysis. By performing nonlinear regression fitting on the experimental signaThe potential capability of low coherence backscattering (LBS) is explored to determine the anisotropy factor based on azimuthal light backscattering map. The scattering intensity signal measured at azimuthal angle φ=0° is extracted for analysis. By performing nonlinear regression fitting on the experimental signal to the Henyey-Greenstein phase function, the anisotropy factor is determined. The experiments with tissue phantom consisting of the aqueous suspension of polystyrene microspheres are carried out. The results show that the measured anisotropy factor is well described by Mie theory..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 470 (2014)
Steering knuckle diameter measurement based on optical 3D scanning
Li-mei SONG, Da-peng LI, Yu-lan CHANG, Jiang-tao XI, and Qing-hua GUO
To achieve accurate measurements, the creating a fitting hole for internal diameter (CFHID) measurement method and the establishing multi-sectional curve for external diameter (EMCED) measurement method are proposed in this paper, which are based on computer vision principle and three-dimensional (3D) reconstruction. TTo achieve accurate measurements, the creating a fitting hole for internal diameter (CFHID) measurement method and the establishing multi-sectional curve for external diameter (EMCED) measurement method are proposed in this paper, which are based on computer vision principle and three-dimensional (3D) reconstruction. The methods are able to highlight the 3D characteristics of the scanned object and to achieve the accurate measurement of 3D data. It can create favorable conditions for realizing the reverse design and 3D reconstruction of scanned object. These methods can also be applied to dangerous work environment or the occasion that traditional contact measurement can not meet the demands, and they can improve the security in measurement..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 473 (2014)
MR image denoising method for brain surface 3D modeling
De-xin ZHAO, Peng-jie LIU, and De-gan ZHANG
Three-dimensional (3D) modeling of medical images is a critical part of surgical simulation. In this paper, we focus on the magnetic resonance (MR) images denoising for brain modeling reconstruction, and exploit a practical solution. We attempt to remove the noise existing in the MR imaging signal and preserve the imagThree-dimensional (3D) modeling of medical images is a critical part of surgical simulation. In this paper, we focus on the magnetic resonance (MR) images denoising for brain modeling reconstruction, and exploit a practical solution. We attempt to remove the noise existing in the MR imaging signal and preserve the image characteristics. A wavelet-based adaptive curve shrinkage function is presented in spherical coordinates system. The comparative experiments show that the denoising method can preserve better image details and enhance the coefficients of contours. Using these denoised images, the brain 3D visualization is given through surface triangle mesh model, which demonstrates the effectiveness of the proposed method..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 10, Issue 6, 477 (2014)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20