基于光纤拉锥及相位调制的可切换多波长掺铒光纤激光器

研究了一种全光纤可切换多波长掺铒光纤激光器。该激光器利用一段缠绕在压电陶瓷上的单模光纤作为正弦相位调制器以及基于光纤拉锥的马赫-曾德尔干涉仪作为梳状滤波器,抑制由于掺铒光纤的均匀展宽效应引起的模式竞争,从而避免了在室温下不稳定的单波长激射,实现了多波长掺铒光纤激光器的稳定输出。实验中观察到稳定的5个波长的同时激射,相邻波长间隔为0.804 nm。信噪比大于40 dB,3 dB带宽约为0.023 nm,中心5个波长输出功率的平坦度为14 dB。同时,激光器具有灵活的波长可切换特性,通过调整驱动信号和偏振控制器的状态,实现了单波长、双波长、三波长以及更多波长的输出。该激光器可应用于大容量波分复用系统和光纤传感。     

波长可切换窄线宽单频掺镱光纤激光器（特邀）

基于光纤环形激光器,设计出由三端口环形器、偏振控制器、未泵浦保偏掺镱光纤和光纤布拉格光栅组成的滤波器件作为高精度滤波器对谐振腔内的模式个数进行抑制,通过调谐偏振控制器,在保偏掺镱光纤内形成的梳状光谱和动态光栅,实现了窄线宽、单、双波长可切换单频掺镱光纤激光器。单波长运行时,在1064.37 nm处测得激光器输出线宽346 Hz,光信噪比大于50 dB,30 min内该激光器波长及功率的不稳定性均在0.01 nm和0.2 dB范围内。通过调节偏振控制器,单波长和双波长可以实现互相切换,双波长分别位于1064.156 nm和1065.236 nm。该技术为超窄线宽激光器的双波长输出提供了新的途径。     

基于NPR效应及NOLM的多波长SOA光纤激光器

为了获得具有超窄波长间隔的稳定多波长输出,设 计并实验验证了一种基于非线性偏振旋转(NPR)效应及NOLM的多波长SOA光纤激光器。利用 SOA的NPR效应,将SOA与其他偏振器件组合引起强度相关损耗(IDL)效应,从而抑制SOA均 匀加宽线宽内的模式竞争,实现稳定的多波长输出。Lyot-sagnac滤波器作为波长选择器件 ,选用71 m长保偏光纤(PMF)得到超窄波长间隔。另外NOLM作为功率 均衡器进一步抑制了模式竞争效应并且实现了功率均衡,提高了边模抑制比(SMSR)。通过调 节偏振控制器(PCs),最终在室温下实现了稳定且功率均衡的多波长输出,10 dB带宽内输出的波长数量为184,波长间隔为0.08 nm,SMSR高达22 dB。该激光器可作为DWDM光通信系统 中的光源。     

采用移频反馈的SOA多波长光纤环形激光器

文章报道了一种基于移频反馈的半导体光放大器(SOA)多波长光纤环形激光器,其环腔内插入声光调制器作为移频器,用自制的光纤马赫-曾德干涉仪进行梳状滤波,在输出光谱1.5 dB带宽为21.7 nm范围内,获得了间隔50 GHz的54个稳定的多波长连续光激射,消光比为28 dB.该激光器具有工作稳定性好、输出光谱宽和不同波长功率平坦度高的优点.实验证明,移频反馈技术能够实现激光器不同起振波长间的增益均衡,使输出光谱带宽增大21.7%.     

采用双Sagnac环滤波器的可切换多波长光纤激光器

提出了一种基于双Sagnac环滤波器的可切换多波长掺铒光纤激光器,该滤波器由基于保偏光纤和少模光纤的Sagnac环并联构成,结构简单,利用其梳状滤波特性,实现了掺铒光纤激光器的多波长输出。采用传输矩阵法详细分析了双Sagnac环的传输特性,进一步搭建了线性腔掺铒光纤激光器,实验中通过调节偏振控制器,改变腔内偏振态,在室温下得到稳定可切换的单、双、三波长激光输出,且激光器输出波长的位置可调。研究结果表明,输出激光波长的边模抑制比大于34 dB,稳定性测量中波长漂移量小于0.05 nm,具有良好的稳定性,可应用于波分复用及全光通信系统等领域。     

双环内级联采样光栅的多波长锁模光纤激光器

为了实现多波长激光输出,提出了一种改进的多波长主动锁模光纤环形激光器,采用集成级联采样光纤光栅进入激光腔形成稳定的多种波长激光的方法,进行了理论分析和实验验证。结果表明,双环形腔结构对于所有波长激光,其腔长度是一致的,从而可以用相同的锁模信号实现所有波长的同步锁模。实验中光纤环形激光器成功实现了以1.6nm为间隔的波长多达14个;它的输出功率大于0dBm,边模抑制比约30dB,最高模式锁模频率为1.05GHz,输出脉冲序列的脉宽是216ps。这一结果对光纤传输系统设计是有帮助的。     

采用F-P光纤环滤波器的窄线宽环形腔光纤激光器

提出了一种采用F-P光纤环滤波器的窄线宽环形腔激光器,该激光器采用环形腔结构,两个耦合比为30:70的耦合器和一段2 m长的未泵浦掺铒光纤构成F-P光纤环滤波器,F-P光纤环滤波器产生的梳状谱,可以增大激光模式之间的自由光谱范围（FSR）,在一定程度上减小跳模现象的发生,有利于模式的稳定。研究表明,通过对掺铒光纤的优化和耦合器的选择可以提高F-P光纤环滤波器的精细度,而F-P光纤环中的未泵浦掺铒光纤起到饱和吸收体的作用,使输出激光的线宽得到有效压缩。将保偏光纤光栅和F-P光纤环滤波器共同应用于环形腔掺铒光纤激光器,在室温下得到了3 dB线宽均小于0.07 nm（实验室光谱仪最小分辨率）的窄线宽双波长输出。在2 h的观测时间内,最大峰值功率波动小于0.4 dB,具有良好的稳定性。     

基于Mach-Zehnder滤波的可调谐光纤激光器

() ()基金项目: 。摘要:为了实现高稳定性的可调谐激光输出,提出并设计了一种基于Mach-Zehnder(M-Z)滤波结构,结合Fabry-Perot(F-P)滤波器的可调谐掺铒光纤激光器,并对激光器的原理及实现方案进行理论分析和实验验证。所设计激光器系统的泵浦源工作波长为976 nm;长度5 m的掺铒光纤作为增益介质;采用全光纤M-Z结构进行滤波,并结合F-P滤波器实现单波长激光可调谐输出。实验中,通过调节F-P滤波器,在泵浦功率为60 mW时,实现了1547～1568 nm范围内单波长激光的稳定可调谐输出,波长调谐间隔小于1.7 nm,每个输出波长的边模抑制比均大于55 dB,线宽均小于0.1 nm。     

工作在L波段的多波长Er3 /Yb3 共掺光纤激光器

采用Er^3 ／Yb^3 共掺双包层光纤(EYDF)作为增益介质，利用一段标准的多模光纤作为空间梳状滤波器，于室温下实现了5个波长的稳定输出。通过调节偏振控制器的状态，可以实现对波长振荡个数和波长间隔的控制。腔中不加任何的稳定装置，在激光输出功率高于207mw时，仍能够得到多波长的稳定振荡，单一波长的线宽窄于0．15nm，边模抑制比大于32dB。通过优化单模光纤与多模光纤的熔接，选择更加合适的多模光纤，可实现更多波长个数的稳定的多波长输出。     

Wavelength-switchable fiber ring laser using cascaded fiber Bragg gratings combined with amplitude modulator

The wavelength-switchable fiber laser has been studied in this paper. A wavelength-switchable erbium-doped fiber ring laser constructed using cascaded five fiber Bragg gratings (FBGs) incorporated with amplitude modulator is achieved and switching over 5 separate wavelengths has been demonstrated. The output power is about −4 dB m, the 3-dB linewidth is less than 0.02 nm, and the side mode suppression ratio is more than 45 dB. The transit process of the wavelength switching from one wavelength to another is studied and the lasing competition is also investigated.     

A stabilized and tunable erbium-doped fiber ring laser with double optical filter

We have proposed and experimentally demonstrated a stabilized and tunable erbium-doped fiber ring laser by using a Fabry-Pe/spl acute/rot laser and a fiber Fabry-Pe/spl acute/rot filter. The sidemode suppression ratio of >30 dB/0.1 nm and the output power of >2.2 dBm can be achieved while this ring laser is tuned from 1528.28 to 1559.64 nm with the step of 1.12 nm. The wavelength variation of less than 0.01 nm and the power fluctuation of /spl les/0.04 dB have also been obtained. When the constant output power is controlled by adjusting the bias current of 980-nm pump laser, the power variation of less than /spl plusmn/0.05 dB can be obtained over the entire tunable range.     

Wavelength-switchable La-codoped bismuth-based erbium-doped fiber ring laser

A wavelength-switchable La-codoped bismuth-based erbium-doped fiber ring laser with the capability to switch to one of 35 lasing wavelengths, spaced at 0.8 nm from 1545 to 1575 nm, is reported. Excellent wavelength stability of better than 1 pm and power fluctuation of less than 0.15 dB were observed during a 2-h stability test.     

平坦功率输出的宽带波长可调光纤环型激光器

为了获得一种平坦功率输出的宽带波长可调的掺铒光纤环型激光器,提出采用一高双折射光纤环镜获得其平坦功率输出,在高双折射光纤环镜中,采用了大量的高双折射光纤段和偏振控制器,它们的反射光谱可补偿掺铒光纤环型激光器输出功率光谱的不平坦,通过压缩或者延伸激光腔里的分布式光纤布喇格光栅即可实现波长调谐。实验验证可以获得一种宽达38nm的宽带波长调谐(1527nm～1565nm),输出功率的不平坦被控制在±0．8dB范围之内,总输出功率大约4dBm、3dB线宽为0．01nm、旁瓣抑制比为48dB的光纤环型激光器。     

Stable and widely tunable wavelength-spacing single longitudinal mode dual-wavelength erbium-doped fiber laser

In this paper, a novel and simple widely tunable wavelength-spacing single longitudinal mode (SLM) dual-wavelength erbium-doped fiber laser (EDFL) based on the tunable filter group, a passive feedback fiber ring (FFR) and saturable absorber (SA), is proposed and demonstrated experimentally. Experiment results show that the wavelength spacing can tune from 0.8 nm up to 17 nm, which has potential to generate terahertz (THz) waves by photo-mixing the lasing wavelengths in a high-speed photo-detector, and the maximum fluctuation of peak power of EDFL is less than 0.37 dB within 75 min and the optical signal-to-noise ratio is more than 30 dB at room temperature. In the absence of high-speed photo-detector, THz beat-note is also successively observed with the help of an autocorrelator. Moreover, dual-wavelength fiber laser can selectively realize one wavelength lasing by simply tuning filters.     

Tunable Fiber Laser Using a Broad-Band Fiber Mirror and a Tunable FBG as Laser-Cavity Ends

By using a broad-band fiber mirror (BFM) and a tunable fiber-Bragg-grating at either end of laser cavity, a wavelength tunable erbium-doped fiber laser is demonstrated. In a forward pump scheme using 100 mW pump power at 1480 nm, stable lasing output power of 21.14-mW measured at 1544.8 nm is obtained with a threshold pump power of 4.7 mW. A side-mode suppression ratio as high as 57.9 dB, wavelength tuning range up to 30 nm with step resolution of 0.2 nm and power variation less than plusmn1.0 dB are achieved. For a backward pump scheme, the BFM acts as a broad-band reflector both for the lasing signal and pump source. The high performance, cost-effective BFM based tunable fiber laser may play an important role in fiber optics communication and fiber sensing applications.     

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.     

基于镀铜长周期FBG的波长可调谐环形光纤激光器

将采用化学镀铜膜技术封装的长周期光纤光栅（LPFG）串人环形腔中,设计了一种新颖的波长可调谐掺Er3＋光纤激光器（EDFL）。铜镀膜（化学涂镀）的LPFG在激光器环腔中用作带阻滤波器,利用恒电流源调节LPFG所处温度场,影响LPFG透射谱,改变激光器环形腔增益最高点,实现输出激光波长的可调谐。在LPFG环境温度调谐20...     

Optimization of the multiwavelength erbium-doped fiber laser in a unidirectional cavity without isolator

Highly uniform multiwavelength erbium-doped fiber ring laser with an intra-cavity sine phase modulator is demonstrated. The flat output spectrum is achieved by optimizing the cavity structure, modulation amplitude and frequency of the sine phase modulator. 15 lasing lines with wavelength spacing of 0.9 nm appear simultaneously and stably in power differences less than 2 dB and the side mode suppression ratio higher than 32 dB. In addition, the proposed cavity can support unidirectional operation without optical isolators. The output power difference of about 20 dB is realized between counterclockwise and clockwise direction, which is almost independent of the pump power and lasing wavelengths.     

掺铥光纤激光器波长可调谐输出特性

利用1 550 nm光纤激光器搭建了一个同带泵浦环形腔掺铥光纤激光器,并对其光谱输出特性进行了研究。在1 550 nm激光泵浦下,1.6 m掺铥光纤自发辐射谱覆盖1 800~1 900 nm范围,3 dB带宽大于60 nm;通过在腔内插入隔离器,获得了线宽小于0.2 nm的激光输出,中心波长在1900 nm附近;进一步在腔内加入FP腔,获得了可调谐的窄线宽输出,光谱调谐范围达60 nm,覆盖从1 840~1 900 nm的光谱范围,激光线宽仅为0.07 nm。另外,在腔内使用通信波段用FP腔,同样获得了较宽调谐范围的窄线宽输出。输出光谱分为1 820~1 850 nm和1 865~1 915 nm两个区域,调谐范围共达80 nm。结合使用2 000 nm FP腔的可调谐光谱范围,该激光器在1 820~1 915 nm的范围都可以获得激光输出,与掺铥光线的自发辐射谱基本相符。     

双光纤光栅法-珀腔可调谐窄线宽激光器

基于游标原理,利用一对自由谱宽(FSR)略有不同的光纤布喇格光栅法布里-珀罗腔(FBG-FP)作为模式选择器件,设计了一种新颖的环形腔光纤激光器。从理论和实验上研究了该激光器的特性。通过对可调谐FBG-FP应力调谐,在1552.240～1552.912 nm范围内,以96 pm为平均间距,获得了8个由固定FBG-FP的透射谱所确定的窄线宽稳定激光输出。8个输出波长的平均功率为-17.66 dBm,波动在0.7 dB范围内。当泵浦光的功率为95 mW的时候,输出信号的信噪比均大于50 dB。实验上每隔1 min用光谱分析仪(OSA)对输出光波长自动扫描,记录的输出光波长漂移在数皮米范围内,且功率的波动小于0.1 dB。这种可调谐的窄线宽光纤激光器在光纤通信和光纤传感方面有潜在的应用价值。