共查询到20条相似文献,搜索用时 31 毫秒
1.
Sub Hur Jeongyun Ko Inkyu Lee Kim Y.S. Jichai Jeong 《Lightwave Technology, Journal of》2003,21(6):1499-1503
We have theoretically investigated 8 /spl times/ 10-Gb/s wavelength-division multiplexing (WDM) signal transmission characteristics based on semiconductor optical amplifiers (SOAs) with equalized gain using discrete Raman amplification (DRA). Gain equalization and low noise figures have been obtained by adjusting the backward Raman pumping power and wavelength at a dispersion compensating fiber (DCF) for each span. Bit-error-rate characteristics were calculated for 8 /spl times/ 10-Gb/s WDM signal transmission over 6 /spl times/ 40-km single-mode fiber (SMF) + DCF links with gain-equalized SOAs using DRAs at DCF. Approximately a 2.5-dB improvement of the receiver sensitivity was achieved by using SOAs and DRAs with optimized Raman pumping. One can easily upgrade the transmission length of a link based on SOAs with an appropriate backward pump laser at each DCF. 相似文献
2.
拉曼光纤激光器的初步研究 总被引:2,自引:0,他引:2
采用标准单模石英光纤作为拉曼增益介质,国产镀膜镜作为谐振腔镜,在1064nm 光纤
激光器的泵浦作用下,在波长1123nm 获得了一级拉曼激光输出。实验观察了激光的形成过程。 相似文献
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Iwatsuki K. Nishi S. Saruwatari M. Nakagawa K. 《Photonics Technology Letters, IEEE》1990,2(7):507-509
Optical soliton transmission of 5 Gb/s over a 23-km amplification spacing using a gain-switched 1.55-μm distributed feedback laser diode and Ti:LiNbO3 intensity modulator is discussed. An Er +-doped fiber amplifier, pumped by 1.45- and 1.48-μm laser diodes, is employed for achieving intense optical pulses. Transmission fiber-loss is completely compensated for by Raman amplification using by 1.45- and 1.48-μm laser-diode pumping. A bit error rate (BER) of 2×10-10 has been obtained 相似文献
5.
This paper investigates Raman amplification and remotely pumped postamplification in repeaterless systems based on standard fiber. Design rules taking into account self phase modulation are presented along with the achievable power budget improvements 相似文献
6.
It is shown that the timing jitter of dispersion-managed soliton systems can be reduced by up to 40% by using a hybrid amplification scheme in which fiber losses are compensated by using erbium-doped fiber amplifiers in combination with backward pumped Raman gain. The jitter is smallest in the case of 100% Raman amplification, but considerable reduction occurs even for partial distributed amplification 相似文献
7.
A UV-grade silica optical fiber was pumped by a 281.8-nm XeBr excimer laser. The first Stokes spectrum was observed at 285 nm. The spectral width was one-half of that of the spontaneous Raman spectrum. A numerical analysis of stimulated Raman scattering which includes two-photon absorption loss is presented. The Raman gain coefficient, determined by an analysis of the nonlinearity observed in the Stokes output, was 1.8×10-5 cm/MW. The analysis also indicates that two-photon absorption is a more important loss factor than linear attenuation. The short wavelength limit of net amplification by stimulated Raman scattering is estimated to be 272 nm 相似文献
8.
The amplification effect on stimulated Brillouin scattering (SBS) and Rayleigh scattering in the backward pumped G652 fibers Raman amplifier have been researched. The signal source is a tunable narrow spectral bandwidth (〈10 MHz) ECL laser and is pumped by the tunable power 1427.2 nm fiber Raman laser. The Rayleigh scattering lines are amplified by fiber Raman amplifier, and Stokes stimulated Brillouin scattering lines are amplified by fiber Raman amplifier and fiber Brillouin amplifier. The SBS lines total gain is a production of the gain of Raman and the gain of Brillouin amplifier. In experiment, the gain of SBS is about 42 dB and the saturation gain of 25 Ion G652 backward FRA is about 25 dB, so the gain of fiber Brillouin amplifier is about 17 dB. 相似文献
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We present an analysis and design method for multiwavelength pumped fiber Raman amplifiers for massive wavelength division multiplexing (WDM) systems with signal bandwidths of 10 to 12 THz and a very large number of channels. We solve self-consistently the optimal design problem for backward-pumped distributed Raman amplifiers with special gain profiles that compensate for the Raman tilt and wavelength-dependent fiber loss. We study the noise performance of these optimally designed amplifiers and address the issues of multispan amplification for long-haul transmission of such broadband signals 相似文献
11.
Saito S. Kimura T. Tanabe T. Suto K. Oyama Y. Nishizawa J.-I. 《Lightwave Technology, Journal of》2003,21(1):170-175
We have fabricated GaP-AlGaP tapered waveguide semiconductor Raman amplifiers, and analyzed the effect of tapering in pulse-pumped high-gain operation. The finesse measurement and 80-ps pulse pumped Raman amplification experiment were performed. Although the tapering has caused additional optical loss, the highest gain of 23 dB has been obtained for a tapered waveguide with input facet of 6.0 /spl mu/m/sup 2/ and back facet of 2.9 /spl mu/m/sup 2/ at averaged input power of 170 mW (peak power 26 W). It is shown that the optical loss of the pump light is more severe than the linear optical loss of the signal light when the gain is higher than 20 dB. 相似文献
12.
Nicholson B.W. Russell J.A. Trainor D.W. Roberts T. Higgs C. 《Quantum Electronics, IEEE Journal of》1990,26(7):1285-1291
Experiments were performed to determine the degree of phasefront preservation possible in a high-gain, large-Fresnel-number number Raman amplifier. Phasefront information was encoded on a Stokes seed, which was then amplified in a 10-atm vibrational hydrogen Raman amplifier pumped by a XeF excimer laser. Interferometric data on the input and amplified Stokes beam indicate that their phasefront difference is less than 0.1 wave RMS. These results are consistent with the predictions of a numerical model of the Raman amplification process 相似文献
13.
We describe the first operation of a high-power semiconductor-laser pumped fibre Raman amplifier (FRA) using high-Raman-gain optical fibre in the 1.5?m region. A high optical gain of 5 dB for 60mW of pump power is obtained. We have also achieved simultaneous amplification of wavelength-division-multiplexed signals by the FRA. 相似文献
14.
Coherent effects produced by high-intensity pumping onaR (6, 0) in NH3 are investigated for both the pure gas and for mixtures with an inert buffer gas. Two different Raman transitions are observed. One is the usual directly pumped Raman transition, and the other is pumped indirectly since it first requires a large population transfer to the upper vibrational level. This population transfer also creates inversion gain, shifted away from line center due to ac Stark shifts, on both transitions. Raman gain coefficients of 10 percent ċ cm-1and inversion gain coefficients > 2 percent ċ cm-1are observed, and compared to a combined density-matrix and rate-equation model. 相似文献
15.
A new method to equalize power imbalance caused by Raman-induced crosstalk among optical channels is proposed using a lumped germanosilicate fiber Raman amplifier. Evolution of optical channels through the Raman amplifier was simulated using Raman frequency modeling, which theoretically predicted simultaneous amplification and power equalization. Experimentally, a gain band with negative slope in the range of 1.571-1.591 μm was achieved in a lumped Raman amplifier pumped by a broad-band laser diode centered at 1.467 μm. We demonstrated compensation of the Raman-induced crosstalk of 5 dB accumulated along 330 km of conventional single-mode fiber 相似文献
16.
《Lightwave Technology, Journal of》2009,27(24):5597-5601
17.
Performance limitation due to statistical Raman crosstalk in a WDM system with multiple-wavelength bidirectionally pumped Raman amplification 总被引:1,自引:0,他引:1
A general theoretical model of statistical Raman crosstalk and its impact on system performance in a multiwavelength bidirectionally pumped Raman fiber amplifier (RFA) is developed for the first time, where we have taken modulation statistics, dispersion-induced pulse walk-off and signal-induced pump depletion into account. Two kinds of statistical Raman crosstalk, from signal-induced forward-pump depletion and from signal-signal Raman interaction, are included in one model. Formulas for normalized Raman crosstalk, Raman crosstalk-induced relative intensity noise spectral density, and its variance and system performance impact in terms of Q penalty are presented for both a single-span system and a dispersion-compensated multispan wavelength-division-multiplexed (WDM) link. Based on these formulas, we numerically investigate the impact of Raman crosstalk on system performance in a three-wavelengths bidirectionally pumped 40 /spl times/ 40-Gb/s WDM system for various fiber types. In addition, Raman crosstalk in a four-wavelength bidirectionally pumped RFA was experimentally measured. The results agree well with our theory. 相似文献
18.
在宽带密集波分复用 (DWDM )系统中 ,后向抽运分布式光纤拉曼放大器 (B DFRA)会引入在小信号条件下无需考虑的两种效应 :抽运饱和效应 (PS)使拉曼增益减小 ;拉曼放大使信道间受激拉曼散射 (SRS)效应增强 ,产生附加拉曼倾斜效应 (ART)。将后向抽运分布式光纤拉曼放大器的增益谱分解为拉曼抽运的放大作用和信道间受激拉曼散射效应产生的倾斜作用 ,通过对各种工作条件下实际后向抽运分布式光纤拉曼放大器增益谱的优化计算 ,研究了抽运饱和效应和附加拉曼倾斜效应对后向抽运分布式光纤拉曼放大器增益谱的影响。计算发现抽运饱和效应取决于信道输出功率 ,附加拉曼倾斜效应由信道输入功率和输出功率共同决定 ,进而通过抽运饱和效应和附加拉曼倾斜效应的大小可以将后向抽运分布式光纤拉曼放大器的工作条件划分为三个区域 ,并讨论了不同工作条件下后向抽运分布式光纤拉曼放大器的简化分析方法 相似文献
19.
An experimental investigation of the conversion efficiency of a high pressure CO2 laser pumped CH3 F Raman laser is reported. We show that resonance absorption of the CO2 laser radiation in the CH3 F gas can lead to a severe limitation of the efficiency. At CO2 laser frequencies where the stimulated Raman action is strongest, a quantum efficiency for conversion of CO2 laser radiation into far infrared radiation of the order of 0.1 is observed. 相似文献
20.
G. Dai F. Tassone A.L. Bassi V. Russo C.E. Bottani F. D'Amore 《Photonics Technology Letters, IEEE》2004,16(4):1011-1013
We describe a highly stable glass family based on the combination of TeO/sub 2/ with heavy metal-oxides of Nb, Ti, W. We show that these glasses have large Raman gain, a broad Raman spectrum, and large negative dispersion. They are, thus, potentially useful in a variety of specialty fiber applications, such as discrete Raman amplification. 相似文献