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The traditional method uses the least squares method to evaluate the effect of satellite load noise on the recovery accuracy of the lunar gravity field, which means large number of complex calculations are needed. In order to recover the lunar gravity field more accurately and simply, the article establishes an expression of the noise power spectrum and analysis the errors from the accuracy of the...
A 1.5 μΜ tunable CW single-frequency seed laser is injected into the methane-filled negative curvature hollow-core fiber, and then amplified by stimulated Raman scattering of methane molecule. The Stokes linewidth is measured at the output using a scanning Fabry-Perot interferometer. When the wavelength of the seed laser is tuned to the Stokes transition and the polarization direction of the seed...
We propose a method to design and implement the microwave photonic filter with rectangular response by using the frequency comb, spatial light modulator-based spectrum shaper and dispersive element. Numerical results are presented to verify the proposed scheme.
A type of newcastle disease virus (NDV) immunosensor based on 81° tiled fiber grating (81° TFG) was proposed. Staphylococcus aureus Protein A (SPA) was used to modify the surface of 81° TFG, then highly purified NDV monoclonal antibodies (MAbs) were immobilized on 81° TFG surface through SPA molecules. The experimental results show that, the immunosensor has a lowest limit of detection (LOD) of 0...
A novel passive optical node with low latency for optical access network (OAN) is proposed, in which the optical circuit just consists of several optical splitters. 1310nm/ 1490nm wavelength division is used in the node. At 1310nm wavelength, any optical network unit (ONU) in one group can transmit the uplink signal to OLT and any ONU in the other group. This realizes communication between two ONUs...
A detailed fiber design was presented for the first time for three-stage non-integer order soliton compression at the wavelength of 1060 nm. A compression factor of 173.52 was realized, and the remained pedestal is only 32.21%.
Coherent optical receivers have been widely used in free-space optical communication. We report on a coherent receiver with a homodyne optical phase-locked loop using a Costas loop. Differing from the conventional configuration, the demonstration in this paper with enhanced dynamic performance using an auxiliary acquisition and locking circuitry is able to achieve fast phase locking to signal laser...
In this paper, a free-space optical (FSO) communication system with supercontinuum source generated by dispersion shift fiber (DSF) from pulsed light modulated by optical switches is designed and constructed. In addition, the experimental results of free-space optical communication between broadband and narrowband light source are compared. Verifying the feasibility of broad-spectrum FSO communication...
We have proposed a novel hybrid software and hardware equalization scheme based on digital zero-padding pre-equalization and differential reception. We have experimental demonstrated a red LED based visible light communication system over 1-meter free space transmission with the measured BER below 7% FEC threshold. The signal is QAM-DMT modulated and the modulation level is varying from 32QAM to 128QAM...
Turbulent environment can highly affect the performance of free space optical (FSO) communication links. Therefore, how to obtain the turbulence intensity is a very important issue. The paper has shown the detailed analysis to calculate the log irradiance variance (σ2R) along with the experimental verification under an indoor laboratory controlled turbulence condition. This paper verifies the consistency...
To solve the phase deviation problem caused by antenna orientation centre deviation during the phase calibration of Monopulse tracking receiver on ship-borne sitcom station, a phase compensation method is proposed to enhance the phase calibration precision. The working principle of monopulse tracking receiver is discussed, the demodulation process of sum and difference signal, and the cause of phase...
This paper investigates the performance of underwater visible light communications (UVLC) systems employing multiple transmitters and/or multiple receivers to exploit the advantage of spatial diversity. Experimental results are further provided to evaluate the error performance of single input multiple outputs (SIMO), multiple inputs single output (MISO) and multiple inputs multiple outputs (MIMO)...
The non-line-of-sight ultraviolet single-scatter approximate model is usually used to study the channel characteristics and system performance due to its simplification. In this paper, a performance evaluation system based on the approximate model is established, which includes four aspects, namely, packet error rate, average transmitting power, bandwidth utilizing efficiency and data transmission...
This paper proposes a statistical method to detection of Topological Charges (TCs) based on calculating the similarity factor (SF) between the instantaneous crosstalk distribution and the standard crosstalk distributions. The values of SF are time-varying, and we set a threshold to recognize TCs. Then, the probability density function (PDF) of the SF is obtained to estimate error rate of TC detection...
The GaAsP/Si dual-junction solar cells have been systematically investigated in our paper by using AMPS (Analysis of Microelectronic and Photonic Structures). Based on the optimized results of single-junction solar cells, we propose a promising method to improve the properties of the dual-junction solar cell. And the monolithic GaAsxP1−x/Si dual-junction solar cells with various As compositions (x=0...
The wavefront compensation effect of the micro corner-cube-reflector arrays (MCCRAs) in modulating retroreflector (MRR) free-space optical (FSO) link is investigated by wave-optics (WO) simulation method that is based on the split-step beam propagation method and phase screen theory. Two kinds of the MCCRAs with the cell's apertures of the triangle and hexagon are considered with the aid of the numerical...
High radio-frequency phase-coded waveform generation based on dispersion-compensated optoelectronic oscillator (DCOEO) is proposed and experimentally demonstrated. The carrier frequency range of the generated phase-coded microwave, which exactly varies from 4 GHz to 45 GHz, can cover Ka band for Radar applications.
The attractive use of microwave photonic (MWP) technologies brings about immense benefits to the field of optical sensing. Recent new developments in microwave photonic signal processing techniques that have high potentialities to be used in a variety of sensing applications are presented in the paper, including exploring the use of finite impulse response MWP filters for distributed sensing applications,...
In this paper, a novel microfiber refractive index sensor prepared with tapering-twisting-tapering technique has been proposed and demonstrated for the first time. Experimental results show that the interference intensity of the novel microfiber increases with the increment of pre-tapered length and the intervening twist number. Furthermore, the refractive index sensitivity of this microfiber sensor...
A new scheme for fabricating microtapered long-period fiber gratings (LPFGs) and helical LPFGs is proposed and demonstrated successfully by periodically tapering and twisting a standard single-mode fiber, respectively, using a CO2 laser fusion splicer as heater. In comparison to previous fabrication methods, our scheme can significantly improve the quality of the microtapered and helical LPFGs. Considering...
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