通过相干合束提高光纤激光源的输出功率是目前研究的一个热门领域,其中多束激光的相位控制是提高合束效率的关键技术之一.本文基于主动相位锁定技术对传统外差探测法进行了改进,基于压电陶瓷及光纤电光相位调制器双通道伺服反馈,实现了...通过相干合束提高光纤激光源的输出功率是目前研究的一个热门领域,其中多束激光的相位控制是提高合束效率的关键技术之一.本文基于主动相位锁定技术对传统外差探测法进行了改进,基于压电陶瓷及光纤电光相位调制器双通道伺服反馈,实现了对同一激光源输出的两路相位独立变化的1531 nm激光长时间的相位锁定.通过选择合适的PID控制参数,将反馈带宽拓展到了220 k Hz(受限于PID控制器自身带宽).最终的相位锁定控制在0.88?以内,即相位控制精度为λ/400,经过160 s平均后可得到相位锁定的最佳值为0.006?,整体实验装置结构简单、运行稳定.展开更多
All-optical regeneration based on self-phase modulation in microstructured fibers is studied. The effects of pulse peak power into the fiber, pulse width and filter parameters on the performance of the regenerator are...All-optical regeneration based on self-phase modulation in microstructured fibers is studied. The effects of pulse peak power into the fiber, pulse width and filter parameters on the performance of the regenerator are investigated. The effects of normal dispersion and anomalous dispersion of the microstructured fiber on optical regeneration are compared. The nu- merical results show that optical regeneration can be achieved by using microstructured fibers with normal dispersion or anomalous dispersion, but the normal dispersion decreases the oscillatory structure in the broadened spectra and obtain a better regenerator transfer function. In order to achieve optical regeneration, the input peak power into the microstructured fiber and the filter parameters need to meet certain requirements. By optimizing those parameters, a better regeneration result can be obtained.展开更多
Numerically analyzed is the transmission performance of the optical millimeter （mm）-wave generated by frequency up-conversion via a phase modulator along the dispersive fiber. 60 GHz ram-wave subcarrier（SC） signal...Numerically analyzed is the transmission performance of the optical millimeter （mm）-wave generated by frequency up-conversion via a phase modulator along the dispersive fiber. 60 GHz ram-wave subcarrier（SC） signals can be obtained after fiber transmission, simultaneously, the phase-modulated signals can be converted to the intensity-modulated ones. The numerical results show that the optical ram-wave at fading loops has better performance, and the eye diagram still keeps open when optical mm-wave signal is transmitted over 98 km.展开更多
In the strapdown inertial navigation system, the Fiber Optical Gyro(FOG) must have high precision to give accurate navigation information. In this paper, a digital closed loop detection method based on the ramp wave m...In the strapdown inertial navigation system, the Fiber Optical Gyro(FOG) must have high precision to give accurate navigation information. In this paper, a digital closed loop detection method based on the ramp wave modulating technigue is introduced. DSP and FPGA have many advantages in digital signal proeessing. In the design, by using DSP, a complex arithmetic operation is completed to meet the needs of closed loop control of FOG within a short time. All kinds of control signals are produced easily by FPGA, under which DSP could work properly. Combining the DSP and FPGA,the detecting method is implemented successfully. In the end, the result of test and performance is given. From the result we can conclude that the precision of FOG is improved and the noises are limited to a low level.展开更多
Micro-displacement measurement based on self-mixing interference using a fiber laser system was demonstrated. The sinusoidal phase modulation technique was introduced into the fiber laser self-mixing interference meas...Micro-displacement measurement based on self-mixing interference using a fiber laser system was demonstrated. The sinusoidal phase modulation technique was introduced into the fiber laser self-mixing interference measurement system to improve the measurement resolution. The phase could be demodulated by the Fourier analysis method. Error sources were evaluated in detail, and the system was experimentally applied to reconstruct the motion of a high-precision commercial piezoelectric ceramic transducer （PZT）. The displacement measurement resolution was well beyond a half-wavelength. It provides a practical solution for displacement measurement based on all optical-fiber sensing applications with high precision.展开更多
A novel scheme for photonic envelope detection and fiber transmission of 24 GHz impulse radio ultra-wideband(IRUWB) signal is proposed based on phase modulator(PM). In the system, an optics assisted envelope detection...A novel scheme for photonic envelope detection and fiber transmission of 24 GHz impulse radio ultra-wideband(IRUWB) signal is proposed based on phase modulator(PM). In the system, an optics assisted envelope detection unit(OAEDU) is used for filtering one of the first sidebands at the output of PM, then this narrow band optical signal transfers over single-mode fiber(SMF), and the envelope of 24 GHz IR-UWB signal is obtained after photodetection(PD) and low pass filter(LPF). The numerical simulation results show that the combination of PM and OAEDU can alleviate the fiber chromatic dispersion(CD) effectively. The proposed system may provide a simple and cost-effective solution for IR-UWB receiver.展开更多
Based on the principle of virtual equivalent gain,the evolution of self-similar pulses in a normal dispersion-decreasing fiber is investigated.The occurrence of wave breaking during the process under highly nonlinear ...Based on the principle of virtual equivalent gain,the evolution of self-similar pulses in a normal dispersion-decreasing fiber is investigated.The occurrence of wave breaking during the process under highly nonlinear conditions and the effect of its revealed four-wave mixing on the process are also analyzed.The results indicate that the pulse spectrum broadeningin the initial stage is dominated by self-phase modulation while by four-wave mixing in the later stage.The more intense nonlinearity is,the faster the pulse evolution converges to the self-similarity synchronously in both the time domain and the spectrum domain.展开更多
文摘通过相干合束提高光纤激光源的输出功率是目前研究的一个热门领域,其中多束激光的相位控制是提高合束效率的关键技术之一.本文基于主动相位锁定技术对传统外差探测法进行了改进,基于压电陶瓷及光纤电光相位调制器双通道伺服反馈,实现了对同一激光源输出的两路相位独立变化的1531 nm激光长时间的相位锁定.通过选择合适的PID控制参数,将反馈带宽拓展到了220 k Hz(受限于PID控制器自身带宽).最终的相位锁定控制在0.88?以内,即相位控制精度为λ/400,经过160 s平均后可得到相位锁定的最佳值为0.006?,整体实验装置结构简单、运行稳定.
基金the National Basic Research Program ofChina (2003CB314906), the Key grant Project of Chinese Ministryof Education (NO.104046),and the Foundation from the EducationCommission of Beijing (XK100130437).
文摘All-optical regeneration based on self-phase modulation in microstructured fibers is studied. The effects of pulse peak power into the fiber, pulse width and filter parameters on the performance of the regenerator are investigated. The effects of normal dispersion and anomalous dispersion of the microstructured fiber on optical regeneration are compared. The nu- merical results show that optical regeneration can be achieved by using microstructured fibers with normal dispersion or anomalous dispersion, but the normal dispersion decreases the oscillatory structure in the broadened spectra and obtain a better regenerator transfer function. In order to achieve optical regeneration, the input peak power into the microstructured fiber and the filter parameters need to meet certain requirements. By optimizing those parameters, a better regeneration result can be obtained.
基金Dr Start-up Fund of Wuyi University,National Natural Science Foundation of China(60677004)
文摘Numerically analyzed is the transmission performance of the optical millimeter （mm）-wave generated by frequency up-conversion via a phase modulator along the dispersive fiber. 60 GHz ram-wave subcarrier（SC） signals can be obtained after fiber transmission, simultaneously, the phase-modulated signals can be converted to the intensity-modulated ones. The numerical results show that the optical ram-wave at fading loops has better performance, and the eye diagram still keeps open when optical mm-wave signal is transmitted over 98 km.
文摘In the strapdown inertial navigation system, the Fiber Optical Gyro(FOG) must have high precision to give accurate navigation information. In this paper, a digital closed loop detection method based on the ramp wave modulating technigue is introduced. DSP and FPGA have many advantages in digital signal proeessing. In the design, by using DSP, a complex arithmetic operation is completed to meet the needs of closed loop control of FOG within a short time. All kinds of control signals are produced easily by FPGA, under which DSP could work properly. Combining the DSP and FPGA,the detecting method is implemented successfully. In the end, the result of test and performance is given. From the result we can conclude that the precision of FOG is improved and the noises are limited to a low level.
基金This work was supported by the National Natural Science Foundation of China （Grant No. 91123015, 51405240）, the Specialized Research Fund for the Doctoral Program of Higher Education （20113207110004）, and the Natural Science Foundation of Jiangsu Province（BK20140925）. Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author（s） and source are credited.
文摘Micro-displacement measurement based on self-mixing interference using a fiber laser system was demonstrated. The sinusoidal phase modulation technique was introduced into the fiber laser self-mixing interference measurement system to improve the measurement resolution. The phase could be demodulated by the Fourier analysis method. Error sources were evaluated in detail, and the system was experimentally applied to reconstruct the motion of a high-precision commercial piezoelectric ceramic transducer （PZT）. The displacement measurement resolution was well beyond a half-wavelength. It provides a practical solution for displacement measurement based on all optical-fiber sensing applications with high precision.
基金supported by the National High Technology Research and Development Program of China(Nos.2013AA013303,2013AA013301 and 2013AA013403)
文摘A novel scheme for photonic envelope detection and fiber transmission of 24 GHz impulse radio ultra-wideband(IRUWB) signal is proposed based on phase modulator(PM). In the system, an optics assisted envelope detection unit(OAEDU) is used for filtering one of the first sidebands at the output of PM, then this narrow band optical signal transfers over single-mode fiber(SMF), and the envelope of 24 GHz IR-UWB signal is obtained after photodetection(PD) and low pass filter(LPF). The numerical simulation results show that the combination of PM and OAEDU can alleviate the fiber chromatic dispersion(CD) effectively. The proposed system may provide a simple and cost-effective solution for IR-UWB receiver.
基金supported by the School Key Fund of South-central University for Nationalities(No.yzz05008)the Hubei Provincial Department of Education(No.Q20101613)
文摘Based on the principle of virtual equivalent gain,the evolution of self-similar pulses in a normal dispersion-decreasing fiber is investigated.The occurrence of wave breaking during the process under highly nonlinear conditions and the effect of its revealed four-wave mixing on the process are also analyzed.The results indicate that the pulse spectrum broadeningin the initial stage is dominated by self-phase modulation while by four-wave mixing in the later stage.The more intense nonlinearity is,the faster the pulse evolution converges to the self-similarity synchronously in both the time domain and the spectrum domain.
