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.     

Tunable dual-wavelength actively mode-locked fiber laser with anF-P semiconductor modulator

A novel actively mode-locked fiber laser for generating dual-wavelength picosecond pulses is proposed by using a Fabry-Perot laser diode as the modulator in the ring cavity. A linear chirped fiber grating was used as a wavelength selector and produces temporal-spectral multiplexing of the pulses in the gain medium to reduce gain cross-saturation effects. About 2-GHz stable dual-wavelength pulses with a wavelength spacing of 0.92 nm at room temperature were experimentally demonstrated and the wavelengths could be tuned in a range of about 3 nm     

Tunable and Switchable Fiber Ring Laser Among Four Wavelengths With Ultranarrow Wavelength Spacing Using a Quadruple-Transmission-Band Fiber Bragg Grating Filter

Four$pi$-phase shifts are introduced in a uniform fiber Bragg grating (FBG) structure to realize a quadruple-transmission-band filter with ultranarrow 40-pm wavelength spacing. Four separate single-wavelength lasings at 1552.60, 1552.63, 1552.67, and 1552.71 nm, and three pairs of dual-wavelength lasings among above four wavelengths, are achieved stably by incorporating the quadruple-transmission-band FBG filter in a fiber ring cavity with a tunable uniform FBG acting as coarse frequency selection. This new kind of laser will be very useful in applications requiring closely spaced and tunable single- or dual-wavelength components.     

Multiwavelength generation in a Raman fiber laser with sampled Bragg grating

Simultaneous continuous-wave multiwavelength operation of a Raman fiber laser is demonstrated with sampled Bragg grating (SBG) at room temperature. The characteristics of multiwavelength fiber ring laser can be easily controlled by adjusting the parameters of the SBG, including the sampling period and the sampling length. In the proposed fiber laser, stable four oscillating wavelengths with 100- and 50-GHz spacing has been achieved, respectively, as well as five oscillating ones with a wavelength spacing of only 25 GHz by varying the sampling period of the SBG.     

10 GHz再生锁模光纤激光器获得光纤超连续谱的研究

报道了利用10GHz再生锁模光纤环形激光器（RML-FRL）获得波长在1528～1563nm连续可调、脉宽为4．6～5．8ps的短脉冲输出作为高稳定的光纤超连续（SC）谱泵浦源。对RML-FRL输出的脉冲直接放大泵浦4．5km色散位移光纤（DSF），得到20dB带宽46．08nm的SC谱输出，经阵列波导光栅（AWG）谱切片后，得到间隔100GHz、中心波长符合ITUT标准的30信道输出，脉宽在6．5～7．8ps，示波器显示任意信道的抖动均值小于1．4ps。     

Tunable multiwavelength fiber ring lasers using a programmable high-birefringence fiber loop mirror

We demonstrate a comb filter with digitally tunable wavelength spacing using a programmable high-birefringence (HiBi) fiber loop mirror (FLM). We then use the HiBi-FLM to implement a tunable multiwavelength semiconductor optical amplifier (SOA)-based fiber ring laser and a tunable multiwavelength all-fiber Raman ring laser. Both lasers exhibit stable room-temperature operation and have a wavelength spacing that is digitally tunable between 1.6 and 3.2 nm. With the SOA-based configuration, we obtain six wavelengths with a spacing of 3.2 nm and 11 wavelengths with a spacing of 1.6 nm; with the all-fiber Raman-based configuration, we obtain four wavelengths with a spacing of 3.2 nm and five wavelengths with a spacing of 1.6 nm.     

Widely tunable chaotic fiber laser for WDM-PON detection

A widely tunable high precision chaotic fiber laser is proposed and experimentally demonstrated. A tunable fiber Bragg grating （TFBG） filter is used as a tuning element to determine the turning range from 1533 nm to 1558 nm with a linewidth of 0.5 nm at any wavelength. The wide tuning range is capable of supporting 32 wavelength-division mul- tiplexing （WDM） channels with 100 GHz channel spacing. All single wavelengths are found to be chaotic with 10 GHz bandwidth. The full width at half maximum （FWHM） of the chaotic correlation curve of the different wave- lengths is on a picosecond time scale, thereby offering millimeter spatial resolution in WDM detection.     

一种高性能环形可调谐光纤光栅激光器研究

研制了一种新型的高性能环形可调谐光纤光栅激光器。该激光器使用980nm LD作为泵浦源,使用长度为10. 8m的新型增益平坦掺铒光纤作为增益介质,采用可调谐光纤光栅滤波器进行波长调谐,调谐范围可达41nm (1528nm～1569nm) ,中心波长可精确调谐到C波段指定的ITU - T标准中心波长处, 3dB 带宽< 0. 08nm, 25dB带宽< 0. 2nm,波长稳定性优于0. 01nm,边模抑制比> 60dB。最大输出功率46. 94mW,功率稳定性优于±0. 02dB,阈值泵浦功率7. 3mW,斜率效率为39. 75%。并分析了不同腔长、不同输出耦合比对输出功率的影响。     

基于保偏光纤光栅的双波长掺铒光纤激光器

提出了一种基于保偏光纤(PMF)中布拉格光栅的波长间隔可调的可开关双波长掺铒光纤激光器(EDFL)。由于和光纤布拉格光栅(FBG)两个反射峰对应的不同波长的两纵模在偏振态上是止交的．从而在均匀展宽的掺铒光纤中增强了偏振烧孔(PHB)效应。这种偏振烧孔效应大大减小了不同模式之间的竞争，因此可在室温下得到稳定的双波长振荡。另一方面。通过调整偏振控制器的状态．即改变腔内的双折射状念，光纤光栅的两个反射峰强度会发生变化。基于以上原理。便形成了对激光振荡模式的选择．即通过调整偏振控制器的状态可使激光器工作在稳定的双波长状态或在两波长之间转换。通过改变加在光纤光栅上侧向应力的大小和方向．可有效控制双波长激射的波长间隔．实验中得到了0．2～1．1nm的可调间隔。     

Wide passband grating multiplexer for multimode fibers

A grating multiplexer in Littrow-configuration is presented, whose passband width-normalized to channel spacing-is comparable with grating demultiplexers. As shown by calculation, a wide passband is attainable by very small input fiber spacing. Using a standard-(50/125 mum)-GI-fiber as transmission fiber, a 1-dB pass-band of 30 nm with a channel spacing of 46 nm is achieved in an 8- channel device. The insertion losses for each channel are in the range 1.4-2.5 dB for 8- or 10-channel devices.     

振幅采样结合相位采样的线性啁啾光纤光栅理论与实验研究

为了增加可调谐光纤激光器的调谐带宽,需要一种具有大信道间隔、大的总带宽、各信道的峰值反射率在带内保持均匀而在带外迅速下降的多信道滤波器.提出了一种基于光纤光栅大信道间隔的多信道滤波器实现方法,采用了振幅采样结合相位采样的线性啁啾光纤光栅,基于矩形函数的采样形式,不需要作单个采样的切趾.用所提出方法可以实现一块模板设计任意信道间隔的光纤光栅.通过理论和实验结果的对比,该设计方法得到很好的验证.     

一种可调谐掺铒光纤激光器的研究

文章基于掺铒光纤在1 550 nm波段的增益特性,利用光纤光栅作为调谐装置,设计了可调谐光纤光栅激光器的简单结构,通过改变光纤光栅的温度对光纤激光嚣的波长进行了调谐.更重要的是实验分析了不同掺铒光纤长度对激光输出功率的影响,在温度为25℃时,实验中分别取10、20和30 m 3种不同光纤长度进行了测试,结果表明,不同长度的掺铒光纤,其阀值不同.     

Switchable dual-wavelength ytterbium-doped fiber laser based on a few-mode fiber grating

The authors propose and demonstrate a simple switchable dual-wavelength Ytterbium-doped fiber laser based on a few-mode fiber grating. The laser can be designed to operate in stable dual-wavelength or wavelength-switching modes, due to the polarization hole burning enhanced by the few-mode fiber grating. The lasing lines may be controlled only by a polarization controller. Stable operation is achieved at room temperature when the wavelength separation is 0.9 nm.     

全光纤型Er/Yb共掺光纤短腔激光器

报道了一种高输出功率、高斜率效率的短腔ErYb共掺杂光纤激光器。激光谐振腔由一段ErYb共掺杂单模光纤与一对布拉格反射波长相同的光纤布拉格光栅(FBG)组成。反射率为60%的光纤光栅用作光纤激光器谐振腔的输出,3dB带宽为016nm。反射率为99%的光纤光栅作为高宽带反射腔镜,同时作为抽运光输入端,3dB带宽102nm。以980nm激光二极管(LD)作抽运源进行实验。使用不同的抽运功率分别测量不同长度的ErYb共掺杂光纤,优化光纤激光器谐振腔得到的最佳长度仅为13cm。即选用13cmErYb共掺杂光纤作为增益介质来制作短腔ErYb光纤光栅激光器,最大输出功率可达11mW,输出功率稳定性<±001dB,抽运阈值功率为35mW,斜率效率为153%,测量其15522nm激光的输出光谱,25dB线宽为03nm,边模抑制比>60dB,波长稳定性为005nm。可用于密集波分复用(DWDM)系统。     

波长间隔为20 GHz的多波长布里渊光纤激光器

设计了一种基于环形腔的双倍布里渊频移间隔的可调谐光纤激光器实验装置。 该实验装置由一个3 dB耦合器、一台可调谐激光源(TLS)、一台980 nm泵浦和一个实现双倍布里渊频移环形腔构成。该结构耦合输出偶数阶Stokes光,从而实现间隔约为20 GHz或0.16 nm的多波长输出。并研究了980 nm泵浦光和BP光功率对输出偶数阶Stokes光波数的影响。当980 nm 泵浦功率固定为26 dBm(400 mW),BP功率为10 dBm时,获得了间隔为0.16 nm的11个稳定激光输出以及36 nm(1530~1566 nm)的可调谐范围。     

Stable Dual-Wavelength DFB Fiber Laser With Separate Resonant Cavities and Its Application in Tunable Microwave Generation

A single-longitudinal-mode dual-wavelength distributed feedback fiber laser with a wavelength spacing of 0.312 nm is proposed and demonstrated. Based on two spatially separated resonant cavities in a single fiber Bragg grating made by a simple method, stable dual-wavelength lasing is established. Then, a 38.67-GHz microwave signal generated by beating the two lasing wavelengths is obtained with a 3-dB bandwidth of ~6 kHz and a frequency drift <5 MHz without any feedback mechanism. As a potential application of this device, a tunable microwave source ranging from 18.67 to 58.67 GHz (with a small discontinuity) is proposed and partially demonstrated     

基于重叠光栅和啁啾光栅的双波长光纤激光器

研究光寻址电位传感器(LAPS)的器件噪声特性 。通过对LAPS半导体场效应器件的结构分析,建 立LAPS的理论模型,并进一步分析LAPS器件噪声信号的来源、种类及特性。以 pH缓冲液中H离子 浓度为检测对象,搭建基于NI采集卡和Labview环境的LAPS测试系统,对影响LAPS信号噪声 特性的光源 波长、光源调制频率、光源强度和Si衬底厚度等因素进行了仿真和实验研究。结果表明,增 大光源波长和光源强度 是提高输出信号幅值和信噪比(SNR)的最有效方法。     

Programmable fiber optic delay line

This paper describes a novel programmable delay line that generates up to 50 ns of true time-delay in discrete 10 ns intervals. The delay line consists of an externally modulated wavelength tunable fiber laser and a six-element wavelength multiplexed fiber Bragg grating array, with the grating spacing set to yield the desired delay     

Multiwavelength Fiber Optical Parametric Oscillator

We demonstrate, for the first time to the best of our knowledge, a multiwavelength fiber ring laser using a continuous-wave dual-pump fiber optical parametric amplifier (FOPA) as gain medium. In the ring cavity, two high-power pumps are injected into a spool of 1-km highly nonlinear dispersion-shifted fiber to generate the parametric gain, and a superimposed chirped fiber Bragg grating is used as the comb-like filter. Benefiting from the high and flat gain of the dual-pump FOPA, seven lasing lines around 1.55 mum with wavelength spacing of 1 nm have been obtained. Each lasing line has a linewidth of as narrow as 20 pm and an extinction ratio of > 30 dB. The proposed mechanism using a dual-pump FOPA as gain medium is a promising alternative for generating multiwavelength laser.     

40-nm-wide tunable fiber ring laser with single-mode operationusing a highly stretchable FBG

We demonstrate a 750-Hz linewidth single-mode erbium-doped fiber (EDF) ring laser with wide tunability using a widely tunable fiber Bragg grating (FBG). The stable single-mode operation is realized by using the FBG as a narrow wavelength-selective element and 4 m of unpumped EDF as a saturable absorber in the cavity. The 40-nm continuous tuning range of 1522-1562 nm is achieved using a highly stretchable FBG that exhibits a filter tuning range of over 52 nm. The grating is prepared with chemically stripped deuterium-loaded fiber to eliminate degrading factors for the grating strength, thereby achieving the wide tunability. The tuning range represents a 3.5-fold increase in wavelength tuning over previous use of FBGs