980nm波段连续光纤激光器的研究进展

980nm波段掺镱光纤激光器在高亮度抽运源和蓝绿光源方面具有广泛的应用前景。首先介绍了980nm波段连续光纤激光器的研究价值、研究难点。然后,介绍了国内外研究机构在980nm波段连续光纤激光器和放大器方面的研究进展和存在的问题。最后对980nm波段连续光纤激光器和放大器未来发展方向进行探讨。     

Wavelength-locking and coherence-collapsed operation of multimode semiconductor lasers induced by external injection

We have experimentally and theoretically demonstrated that residual power from a fiber Bragg grating-stabilized 980-nm pump laser in a coherence-collapsed state can be used to lock the wavelength of another solitary 980-nm pump. The coherence collapsed operation is transferred to the slave laser.     

一种线形腔的多波长布里渊掺铒光纤激光器

布里渊掺铒光纤激光器(BEFL)是一种利用非线性效应——布里渊散射来实现多波长输出的激光器,波长间隔大约为0.088 nm(11 GHz).研究了一种多波长布里渊掺铒光纤激光器线形结构,通过引入反馈实现多波长输出.在布里渊泵浦功率为11 mW,980 nm泵浦功率为12 mW时获得了波长间隔为0.08 nm的34个波长的激光输出以及1 525～1 570 nm可调谐范围.并通过调节980 nm抽运光功率以及布里渊泵浦光波长,实现了可调谐的多波长输出.还研究了980 nm抽运光功率对产生的斯托克斯光波数的影响.     

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。     

Calculation of the noise figure of erbium-doped fiber amplifiersusing small signal attenuations and saturation powers

A theory allowing the noise figure of an erbium-doped fiber amplifier to be computed with a reduced set of fiber parameters is evaluated. The approach is accurate when the amplified spontaneous emission has no significant influence on the gain. Then four parameters, saturation power and absorption coefficient for pump and signal wavelength, are sufficient for 980-nm pumped fiber amplifier. This theory is used to investigate the noise characteristics of a 980-nm pumped booster amplifier within the whole gain spectrum     

适用于光纤放大器的Er3 -Yb3 共掺双包层光纤

研制出一种适用于光纤放大器的Er^3＋-Yb^3＋共掺双包层光纤（EYDCF），它在980nm和1530nm的吸收分别达到16．8dB／m和20．6dB／m，980nm吸收带半高宽达到200nm。在波长为980nm、泵浦功率为2w的条件下，可以得到28．8dBm（760mW）的输出，相比掺Er^3＋光纤（EDF），EYDCF的增益高，所需光纤长度短，所以非线性效应的发生得到抑制。     

高性能低成本的C+L波段掺铒光纤光源

为了得到一种高性能的C+L波段的宽带掺铒光纤光源,用一个980nm和一个1480nm激光二极管作为抽运源,用两个3dB宽带耦合器作为光纤反射镜,同时利用功率控制电路让光源输出光稳定,对设计的光源进行了实验和理论验证,获得了功率为168.67mW(22.27dBm)、带宽达到80.701nm(1525.112nm～1605.813nm)的C+L波段宽带光源。结果表明,开始用两个980nm和一个1480nm二极管作为抽运源,之后改为一个980nm和一个1480nm二极管作为抽运源,并没有减少光源的输出功率,也没有改变稳定性。这一结果对减少光源的成本、提高光光转换效率,具有实际价值。     

A comparative study of an erbium doped fiber amplifier pumped at811 and 980 nm

The gain and saturation characteristics of an erbium doped fiber amplifier pumped in both the 800 nm and 980 nm pump bands are presented. The maximum gain coefficients are found to occur at the same fiber lengths for both 811 nm and 980 nm pumping. They are 1.2 dB/mW and 7.8 dB/mW, respectively. The amplifier thresholds at both pump wavelengths are quantitatively compared using a simple model and measured attenuation coefficients. Signal amplification at 1533 nm is found to suffer more from the effects of excited state absorption than signal amplification at 1553 nm     

Experimental comparison of 980 nm and 1480 nm-pumped saturatedin-line erbium-doped fiber amplifiers suitable for long-haul solitontransmission systems

The performances of 980-nm- and 1480-nm-pumped erbium-doped fiber amplifiers applicable to high-bit-rate, long-haul soliton transmission systems are compared. Depending on the system parameters and preferred pumping configuration, 980-nm pumping is likely to offer a noise figure advantage of between 1.0 and 1.5 dB. However, the tolerances on pump wavelength are significantly tighter around 980 nm than at 1480 nm     

间隔0.256 nm的多波长布里渊光纤激光器的实验研究

使用一个四端口环行器和两个三端口环形器,设计了一种波长间隔为0.256 nm的多波长布里渊掺铒光纤激光器。该激光器中使用的两个三端口环行器组成的环腔产生一阶Stokes光,四端口环行器组成的环腔产生与入射进腔内的BP光相隔双倍布里渊频移的Stokes光。实验测试得到:当BP为3 dBm、980 nm泵浦功率为27.78 dBm时,可得到波长间隔为0.256 nm的6个波长的激光输出,同时也讨论了Stokes光的数量与BP光功率和980 nm泵浦光功率之间的变化关系。     

间隔双倍频移的可调谐多波长布里渊/铒光纤激光器

设计了一种结构简单的波长间隔双倍布里渊频移的可调谐多波长布里渊/铒光纤激光器。利用一个3 dB耦合器形成复合环形腔结构,使奇数阶斯托克斯信号被局限在一个腔内循环,仅有初始布里渊抽运信号和偶数阶的斯托克斯信号能够耦合输出,实现了波长间隔双倍布里渊频移的多波长输出。分析了不同布里渊抽运功率、不同980 nm抽运功率下激光器的输出特性。在布里渊抽运信号功率10 dBm,980 nm抽运功率110 mW的情况下,激光器在1555~1565 nm范围内获得了波长间隔0.176 nm的6个波长输出。     

High-power EDFA applied in distributed optical fiber Raman temperature sensor system

In this paper, a high-power erbium-doped fiber amplifier (EDFA) for the temperature sensor system is theoretically designed and experimentally demonstrated. It consists of an erbium-doped fiber that is pumped bidirectionally with two 980-nm high-power laser diodes (LDs). At the EDFA input, an optical isolator (ISO) is used to ensure that the signal pulse transmits forward only. After that, a wavelength division multiplexer (WDM) is employed to combine the forward pump laser (980 nm) and incident optical pulse (1550nm) into the erbium-doped fiber for direct amplification in the optical domain. At the EDFA output, another WDM couples the backward pump laser (980 nm) into the erbium-doped fiber and outputs the amplified optical pulse (1550 nm) with an ISO followed to isolate the backscattering light. According to this structure, we carried out the experiment in the condition as follows. For 980 nm pump LD, the operating current is 590 mA, and the setting temperature is 25℃. For EDFA, the length of erbium-doped fiber is 12.5 m, and the power of 1550 nm input signal is 1.5 mW. As a result, the power of pump LD is 330 mW, and the power uncertainty is 0.5%. The power of EDFA output at 1550 nm is 300 mW, and the power uncertainty is ±3 mW.     

掺铒光纤放大器光谱特性和噪声特性的研究

报道了利用 980nm波长的单抽运光源抽运掺铒光纤得到的放大自发辐射谱 (ASE谱 )特性 ,对在较小抽运功率条件下得到的掺铒光纤荧光谱特征图进行了探讨 ;在此基础上对采用两个980nmLD作抽运光源的掺铒光纤放大器 (EDFA)的噪声特性进行了实验研究 ,得到具有良好噪声特性的结果     

掺Yb3+光纤环形激光器特性研究

本文利用国产半导体激光器泵浦掺Yb3+光纤环形激光器获得成功．掺Yb3+光纤长3 m,与1053 nm／980 nm波分复用器(WDM)构成交叉耦合型全光纤环形腔．总腔长为4 m,泵浦波长980 nm,激光波长为1042．3 nm,斜率效率9．6％,激光阈值低于0．5 mW,利用可调谐钛宝石激光器泵浦,得到该光纤激光器的最佳泵浦波长为978 nm．     

High-power and tunable operation of erbium-ytterbium Co-doped cladding-pumped fiber lasers

We describe erbium-ytterbium co-doped fiber lasers in different free-running and tunable configurations. The lasers were cladding-pumped by high-power multimode diode sources. We compare pumping at 915 and 980 nm. With a free-running laser, we obtained slope efficiencies of up to 50% with 915-nm pumping and 38% with 980-nm pumping, with respect to absorbed pump power. We reached a double-ended output power of 16.8 W from the free-running laser. Thanks to a high rare-earth concentration and a small inner cladding area (possible with the high-brightness pump sources we used), the operating pump absorption of the fiber reached 8 dB/m. With such high absorption, short fibers with high nonlinear thresholds are possible even with cladding pumping. The tunable fiber laser had a tuning range from 1533 to 1600 nm and emitted 6.7 W of output power at 1550nm in a high-brightness, single-polarization, narrow linewidth beam.     

Tunable and narrow linewidth multi-wavelength Brill- ouin-erbium fiber laser using dual-wavelength pumping

We demonstrate a multi-wavelength Brillouin-erbium fiber laser (BEFL) with narrow linewidth and tunable wavelength interval using dual-wavelength Brillouin pumping. The generation of multi-wavelength output in BEFL is based on the combination of stimulated Brillouin scattering (SBS) and four-wave mixing (FWM) effect in a fiber cavity. The tunable wavelength interval is determined by the artificially controlled wavelength interval of the pumping lasers. The BEFL could compress a 1 MHz pump laser to a 340 Hz Brillouin Stokes laser, which proves the BEFL has excellent capability of linewidth compression. An erbium-doped fiber pumped by 980 nm laser is inserted into the cavity to further amplify the Brillouin laser. The wideband multi-wavelength BEFL covering over 50 nm is successfully generated when the 980 nm pump power is 400 mW. These features of multi-wavelength BEFL provide an effective method for optical communication systems and optical fiber sensing.     

Tunable multiwavelength Brillouin-erbium fiber laser with a polarization-maintaining fiber Sagnac loop filter

We demonstrate the generation of 12-wavelength comb with 14.5-nm tunable range in the Brillouin-Erbium fiber laser. This is achieved through tuning the gain profile of Erbium-doped fiber by a Sagnac loop filter with 18-cm polarization-maintaining fiber, in conjunction with modifying the wavelength of Brillouin pump. The experiment also demonstrates that the tunable range is closely equal to the 3-dB bandwidth of Sagnac loop filter due to its periodic transmission profile. Meanwhile, the effect of the 980-nm pump on the tunable multiwavelength generation is investigated. The power of 980-nm pump has a great effect on the wavelength number and the output power of the generated multiwavelength comb, but little on the tunable range. This technique may be applicable to multiwavelength operation lasers with a large tunable range.     

Spectral dependence of the small-signal gain around 1.5 μm inerbium doped silica fiber amplifiers

A simple theoretical analysis of small-signal Er³⁺-doped silica fiber amplifier is presented, comparing the efficiency of the 800-, 980-, and 1500-nm pump bands, and demonstrating that wide bandwidth and high gains can be achieved simultaneously by a suitable choice of pump power and fiber length. The comparison shows that the 980- and 1500-nm pump bands have much the same efficiency in terms of dB/mW, and that the 800-nm pumped amplifier is able to produce high gains but at nearly an order of magnitude higher pump powers     

A temperature-insensitive erbium-doped fiber amplifier for terrestrial wavelength-division-multiplexing systems

We have evaluated a variation in the temperature dependence of an erbium-doped fiber gain spectrum by a pump wavelength in the 980-nm band for the first time. By optimizing both the pump wavelength in the 980-nm band and a temperature-sensitive gain flattening filter, the gain change of an erbium-doped fiber amplifier was successfully suppressed to 0.18 dB/sub pp/ in the temperature range between 0/spl deg/C and 65/spl deg/C and the wavelength range of 37.0 nm.     

AlGaAs-InGaAs slab-coupled optical waveguide lasers

The slab-coupled optical waveguide laser (SCOWL) concept, recently proposed and demonstrated, is extended to the AlGaAs-InGaAs-GaAs material system. Both 980- and 915-nm SCOWL devices feature a nearly circular large-diameter single-spatial mode that can be butt coupled with high efficiency to a single-mode fiber. Single-ended continuous-wave output powers of greater than 1 W have been obtained at 980 nm.