基于FP-LD强反馈的光纤迈克尔逊干涉仪传感系统

针对采用传统自组光纤激光器的光纤传感系统存在成本较高和结构复杂等问题,提出了一种基于商用激光器强反馈的光纤迈克尔逊干涉仪(FMI)传感解调系统。该系统采用商用法布里-珀罗腔型半导体激光器(FP-LD)为光源,由直流电源直接驱动,经FMI的反射、干涉后对其形成强反馈;利用多纵模激光拍频解调技术实现对FMI的传感解调,将FMI光域干涉光强的变化直接转化为电域拍频包络的变化。研究了不同FMI臂长差时拍频信号随温度的变化过程及传感系统灵敏度。实验结果表明:当臂长差分别为0.45、0.40 m时,灵敏度分别为325、358.33 kHz/℃。     

光纤激光器的研究进展及趋势

光纤激光器具有光束质量好、体积紧凑、易于集成、抗干扰能力强等优点,是目前研究的热点领域之一。本文介绍。了光纤激光器的基本原理,重点阐述了其发展历史和最新研究进展,最后对光纤激光器的未来发展趋势,特别是大功率、高亮度的光纤激光器进行了分析。     

基于微纳光纤脉冲压缩器的皮秒脉冲掺镱光纤激光器

1.0 m波段的超短脉冲激光器在激光加工、光学精密测量和生物医学等领域具有重要应用价值,但由于掺镱光纤激光器工作在全正色散区域,激光器直接输出的脉冲通常宽度较大。文中利用改变微纳光纤尺寸可以使其在1.0 m波段提供反常色散的特点,将微纳光纤作为色散补偿元件在掺镱光纤激光器腔外对脉冲进行压缩来获得超短脉冲。实验中,自主拉制的微纳光纤锥腰直径为3 m,锥腰长度为5 cm。掺镱光纤激光器直接输出脉冲宽度为37.6 ps,经微纳光纤压缩后脉冲宽度为8.5 ps。该结果提供了一种更简便低廉的压缩脉冲方法。     

高功率光纤激光器研究进展

高功率掺镱双包层光纤激光器由于在效率、散热和光束质量方面的优势,在工业加工、医疗和国防等领域具有广泛的应用前景,是目前国际上激光技术研究的热点之一.首先综述了国际上高功率光纤激光器的研究进展情况,然后重点介绍了中国科学院上海光学精密机械研究所在连续光纤激光和脉冲光纤激光方面所取得的进展,采用双端泵浦技术,在15 m的国产双包层光纤中获得440 W的连续输出,采用MOPA方式,以4 m长的国产光纤作为放大介质,在100 kHz时,获得了133 W的平均功率输出.     

基于石英玻璃掺铥光纤的单纵模DBR光纤激光器的研制

研制了一种具有频率调谐功能的2μm波段分布Bragg反射(DBR)型单纵模光纤激光器。该激光器基于石英玻璃单模掺铥光纤和793 nm半导体激光器泵浦源,其光电器件分离集成在1U机箱内。通过内置压电陶瓷(PZT),可实现对激光频率的快速调谐,调谐范围约6 GHz;通过TEC温度控制,可实现对激光频率在29 GHz范围内无跳模调谐。单纵模激光输出功率为18.2 mW,输出激光信噪比大于60 d B,泵浦转换效率达27%。该激光器样机可望在高分辨光谱、量子信息以及非线性频率变换等领域发挥重要作用。     

光纤饱和吸收体掺镱全光纤化激光器

报道了一种基于光纤饱和吸收体的掺镱全光纤调Q激光器,为了获得较高峰值功率较窄脉宽的激光脉冲输出,利用掺镱光纤的可饱和吸收效应,以20/130 μm规格的大模场双包层掺镱光纤作为增益光纤,以10/130 μm规格的单模双包层掺镱光纤作为可饱和吸收体来实现被动调Q。该激光器采用全光纤化的结构,结构紧凑,以较低的成本获得了较为高效的脉冲输出。最终获得了平均功率最高为3 W,直线效率约为30%,重复频率为10~100 kHz可调,脉宽最窄为344 ns,光谱宽度为0.05 nm、中心波长为1 064 nm的激光输出。     

光纤光栅振动传感信号解调技术的研究

研究了一种基于掺Er超荧光光源(EDSFS)的滤波解调方法,分析了光源的输出功率谱形状。利用光谱中光功率密度与波长的线性关系,实现了光纤光栅传感信号的动态解调。建立振动测试系统,采用高精度差分变压器式位移传感器作为参考,对比讨论了两种传感器输出的时域波形和频谱。结果表明,在相同的条件下,二者的动态响应特性具有很好的一致性。由于系统的光源和解调部分合为一体,无机械调谐元件,很适合高速动态测量。     

基于非线性环形放大镜和微纳光纤锁模激光器的研究现状

被动锁模光纤激光器是超快激光家族中的重要成员,凭借光纤的优良特性,如鲁棒性好、结构简单紧凑、稳定可靠等,吸引了相关研究者的广泛关注。近年来,随着光纤制备工艺和锁模技术的不断进步,光纤锁模激光器得到了迅速发展。基于此,描述锁模技术及不同色散区的锁模激光器,并依据锁模机制、脉冲性质等分类叙述,综述了国内外该领域的研究现状和发展趋势,重点阐述全光纤非线性环形放大镜和微纳光纤锁模激光器的研究进展。     

1μm光纤激光器的研究进展

1μm光纤激光器主要以掺杂Yb3+的光纤为增益介质,在高功率泵浦源、激光雷达、医疗以及科学研究等领域有重要的应用前景.介绍了1 μm掺Yb3+光纤激光器的能级结构和产生原理,对其国内外的发展状况进行了综述,并深入分析各类型光纤激光器的关键技术和解决措施,并对1 μm光纤激光器的发展趋势进行了展望.     

大功率半导体激光器阵列光束光纤耦合研究

从半导体激光器的光参数积出发，给出了一种集光束准直、整形、聚焦及耦合的高功率半导体激光器阵列光束的光纤耦合方法。推导出了正交的两组准直微透镜阵列的面形公式；计算了准直光束的准直精度和聚焦光学系统参数。作为例子，给出一个光纤芯径为800μm，数值孔径0．37的光纤耦合高功率半导体激光器实验结果．其耦合效率大于53％。     

扬氏光纤干涉仪测量激光谱线线宽

本文介绍了一个用二根单模光纤组成的扬氏干涉仪来测量连续或脉冲激光谱线宽度的方法,实测了几种激光的线宽及铜蒸气激光在一个脉冲时间内光谱线宽的时间过程。     

半导体激光干涉仪在微振动测量中的应用

文中介绍一种用半导体激光器构建小型迈克尔逊干涉仪实现对微振动量精确测量的方法,实验证明,这种方法完全可以实现。用这种方法构建的微振动传感器体积小、质量轻、价格便宜并具有很高的灵敏度和准确度     

一种新型的多光束光纤干涉仪

提出了一种新型的多光束光纤干涉仪,测试了它的一些性能.与已有的多光束光纤干涉仪相比,具有一定的特点.     

Stable and high-performance multiwavelength erbium-doped fiber laser based on fiber delay interferometer

In this paper, we proposed a novel scheme to realize the multiwavelength erbium-doped fiber lasers. By adding a length of dispersion shifted fiber (DSF) in the ring cavity, we can suppress the cavity mode competition resulting from homogeneous line broadening (HLB) effect. In addition, a comb filter based on fiber delay inter-ferometer (DI) is used for frequency selecting. To enhance the extinction ratio while maintaining the free space range (FSR), the proposed isolator-assisted double-pass DI is utilized into the laser cavity, and a stable 7-wavelength simultaneous lasing spaced at 21.5GHz is accordingly achieved with an extinction ratio of higher than 40 dB. The lasers are stable with a maximum power fluctuation per channel of less than 0.6 dB during an hour test.     

Distributed optical fiber perturbation sensing system based on Mach-Zehnder interferometer

A novel distributed optical fiber vibration-sensing system based on Mach-Zehnder interferometer has been designed and experimentally demonstrated. Firstly, the principle of Mach-Zehnder optical path interferometer technique is clarified. The output of the Mach-Zehnder interferometer is proportional to the phase shift induced by the perturbation. Secondly, the system consists of the laser diode (LD) as the light source, fiber, Mach-Zehnder optical interferometers as the sensing units, a 1×N star fiber-optic coupler, an N×1 fiber-optic coupler, a photodiode (PD) detector, and a computer used in signal processing. The entire monitoring region of this system is divided into several small zones, and each small monitoring zone is independent from each other. All of the small monitoring zones have their own sensing unit, which is defined by Mach-Zehnder optical interferometer. A series of sensing units are connected by the star fiber-optic couplers to form a whole sensing net. Thirdly, signal-processing techniques are subsequently used to calculate the phase shift to estimate whether intruders appear. The sensing system is able to locate the vibration signal simultaneously, includ-ing multiple vibrations at different positions, by employing the time-division multiplexed (TDM) technique. Finally, the operation performance of the proposed system is tested in the experiment lab with the conditions as follows: the number of the sensing units is 3, the length of the sensing fiber is 50 m, and the wavelength of the light diode is 1550nm. Based on these investigations, the fiber surrounding alert system is achieved. We have experimen-tally demonstrated that the sensing system can measure both the frequency and position of the vibration in real time, with a spatial positional resolution better than 50 m in an area of 1 km2.     

基于半导体光放大器和取样光纤光栅结合Sagnac环的多波长光纤激光器

Multi-wavelength fiber ring laser based on the semiconductor optical amplifier(SOA)with sampled fiber Bragg grating(SFBG)in a Sagnac loop interferometer as the wavelength-selective filter is proposed.Four lasing wavelengths with 1.8 nm spacing have been generated stably at room temperature.The proposed laser has the advan-tages such as removal of the high-cost circulator,flexibility in channel-spacing tuning,and simple all-optical fiber configuration,which has potential applications in high-capacity wavelength-division-multiplexed(WDM)systems and mechanical sensors.     

Sagnac干涉式光纤水听器传感特性理论研究

从理论上分析了Sagnac光纤水听器传感特性与信号频率、探头传感光纤长度、延时光纤长度之间的关系.分析结果表明,Sagnac光纤水听器对于相同的信号频率,其声压相位灵敏度变化周期仅与探头在Sagnac环中位置有关,延时光纤长度增加,声压相位灵敏度周期随之变短.水听器声压相位灵敏度的幅值仅与传感光纤长度有关,传感光纤长度增加,水听器声压相位灵敏度随之提高.仿真计算验证了理论分析结果,对Sagnac光纤水听器的设计和应用有一定的指导意义.     

Multiwavelength fiber ring laser source based on a delayed interferometer

A multiwavelength fiber laser source is demonstrated with a semiconductor optical amplifier as the gain medium. A delayed interferometer is incorporated in the ring cavity serving as a comb-like multichannel filter. A stable 75-wavelength simultaneous operation spaced at 40 GHz with the extinction ratio of 40 dB is achieved. By tuning the cavity loss, the center wavelength of the generated lasing waveband could be varied by as much as 20 nm.     

光纤F-P传感低相干信号的小波提取研究

研究了Morlet小波在光纤Fabry-Perot(F-P)低相干干涉条纹包络提取方面的应用,给出了Morlet小波尺度的计算公式。对不同信噪比(SNR)下低相干干涉峰值的提取作了仿真计算,并利用实测干涉图作了小波提取实验,验证了Morlet小波处理方法的有效性。实验结果显示,采用Morlet小波处理的低相干干涉解调方法的测量线性度好,线性相关系数为0.999 9。     

A variable coefficient microwave photonic filter based on multi-wavelength fiber laser and Mach-Zehnder interferometer

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 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.