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11.
Guanshi Qin Tatsuya Yamashita Yusuke Arai Yasutake Ohishi 《Optics Communications》2007,279(2):298-302
We demonstrate a 22 dB all-fiber amplifier at 546 nm using Er3+-doped fluoride fiber by forward upconversion pumping of a 974 nm laser diode. The gain saturation effects and the power conversion efficiency of this amplifier are investigated in detail based on gain characteristics and numerical simulations. 相似文献
12.
Samudra Roy 《Physica D: Nonlinear Phenomena》2007,232(2):103-107
We try to derive some explicit equations for predicting the laws which govern the evolution of different parameters of a propagating optical pulse in a nonlinear medium under the combined influence of two-photon absorption and gain dispersion. Using the generalized Euler-Lagrange equation, the dynamics of different pulse parameters are generated. The Rayleigh’s dissipation function is incorporated in order to take recourse to the dissipative part, with an analogy with the non-conservative frictional problem in classical mechanics. It appears from the study that the influence of the dissipative part can well be explained using the proposed model. The analytically predicted results are compared with the numerical data obtained from direct simulation of the Ginzburg-Landau equation and the results are found to be quite satisfactory, supporting the prediction. 相似文献
13.
In this paper the gain characteristics of two-pump fiber optical parametric amplifiers (FOPA) with two-section highly nonlinear fibers are analyzed numerically and the parameters of the fibers are optimized to reach broad and flat gain spectra using genetic algorithm. Different from the previous methods, here the space between two pump wavelengths and the parameter β4 of the fibers are included as a pivotal factor in the optimization. The numerical simulation shows that using two-section practical high nonlinear fibers, the amplifier may reach 110 nm bandwidth covering 1495–1605 nm with 10.5 dB average gain and gain ripple of 0.17 dB, when the total pump power is 1 W. 相似文献
14.
Xie Wen Xiong Caidong Wang Xiangru Wang Zhigang Liu Yuming 《International Journal of Infrared and Millimeter Waves》2008,29(4):406-415
In this paper, a new type of gain guiding fiber is presented, with a parabolic-profile for both the gain and index guiding.
Theoretical investigation shows that the core diameter of such fiber may be up to 200 μm while propagating with single-mode. 相似文献
15.
16.
We present a physical and computational procedure to calculate the gain in a two-wave mixing process in a thick optically active photorefractive BSO crystal under diffusion regime. The procedure is based on the integration of the amplitude of the signal beam through the sample. In the model, the effects of self-diffraction are taken into account by using the more general expression of the diffraction efficiency for the case of dynamic gratings. It allows also including the effects of the optical activity on the coupling factors and not only on the rotation of the optical field vectors when the waves are propagated along the crystal. The <001> crystallographic configuration is used. The model is used to predict the behavior of the gain as a function of the beam polarization angle. Numerical and experimental results using crystals with thickness of 5 mm and 10 mm are presented. A good agreement between the proposed model and the experimental measurements is observed. 相似文献
17.
This paper aims to evaluate a comprehensive numerical model based on solving rate equations of a thulium-doped silica-based fiber amplifier. The pump power and thulium-doped fiber (TDF) length for single-pass thulium-doped fiber amplifiers (TDFA) are theoretically optimized to achieve the optimum gain and noise figure (NF) at the center of S-band region. The 1064 nm pump is used to provide both ground-state and excited state absorptions for amplification in the S-band region. The theoretical result is in agreement with the published experimental result. 相似文献
18.
U. Woggon O. Wind F. Gindele E. Tsitsishvili M. Mü ller 《Journal of luminescence》1996,70(1-6):269-280
The optical transition energies have been determined for the lowest electron-hole pair states of CdSe quantum dots embedded in glass. The data obtained by photoluminescence, differential absorption and photoluminescence excitation spectroscopy have been compared and a general size dependence could be established. Based on theoretical calculations, the dominant features in the spectra have been assigned to the different transitions from the ground state to the one-pair states. Within the lowest one pair transition, a fine structure due to exchange interaction has been observed. The change in the optical properties with increasing intensity has been studied and the two-pair states identified in luminescence. Spectrally broad optical gain has been found due to stimulated transitions involving both one- and two-pair states. 相似文献
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20.
A gain-clamped two-stage L-band EDFA is demonstrated by simply incorporating two different FBGs on both side of EDF in the second stage. It forms a FBG laser at 1560 nm to clamp the gain in the system. The gain is clamped at about 16.5 dB with gain variation of less than 1.0 dB at dynamic range up to −10 dBm. A flat gain is obtained over 30 nm of wavelength range from 1568 to 1598 nm with a gain variation of less than 1.1 dB. At the flat region, the noise figure varies from 5.0 to 5.8 dB, which is slightly higher compared to those of unclamped amplifier. The advantage of this technique is that the FBG laser does not disturb the WDM signals in the flat gain region. 相似文献