共查询到20条相似文献,搜索用时 15 毫秒
1.
We demonstrate a period poled tapered lithium niobate waveguide and study second harmonic generation (SHG) in this device for the purpose of broadening the quasi-phase matching (QPM) acceptance bandwidth. The finite-difference beam-propagation method is used to simulate the guided modes and calculate the effective indices. The simulation results show that by tapering the width of the cross section linearly, the phase mismatch between a specific input wavelength and its SHG signal can be varied along the propagation length. Ideal SHG phase-matching conditions for a wide range of input wavelengths in communication band from 1 542.5 nm to 1 553.5 nm can be satisfied in different positions of the waveguide. 相似文献
2.
Electric-field thermally poled optical fibers for quasi-phase-matched second-harmonic generation 总被引:1,自引:0,他引:1
V. Pruneri P.G. Kazansky 《Photonics Technology Letters, IEEE》1997,9(2):185-187
We report on quasi-phase-matched frequency doubling to the blue in electric-held poled optical fibers. An increase of a factor of /spl sim/10 in the conversion efficiency in comparison with the previous results is obtained. Our experiments show that the structure of the induced nonlinear grating is not uniform, both longitudinally and transversely. For this reason the value of the effective nonlinear coefficient is still far from the optimum expected from the measured value, through Maker's oscillation, for a uniformly poled fiber. 相似文献
3.
Yamazaki E. Takada A. Yamawaku J. Morioka T. Tadanaga O. Asobe M. 《Electronics letters》2004,40(8):492-494
Widely tunable multichannel wavelength conversion using a multiple wavelength quasi-phase-matched LiNbO/sub 3/ waveguide is proposed. Simultaneous conversion of four-channel signals with a tunable range of more than 35 nm is successfully demonstrate for the first time. 相似文献
4.
Lallier E. Pocholle J.P. Papuchon M. Grezes-Besset C. Pelletier E. De Micheli M. Li M.J. He Q. Ostrowsky D.B. 《Electronics letters》1989,25(22):1491-1492
Laser oscillation in an Nd:MgO:LiNbO/sub 3/ single-mode channel waveguide has been demonstrated. Under IR dye laser pumping, a threshold of 1.5 mW and a slope efficiency of 14% were achieved. Laser oscillation has also been observed with diode pumping.<> 相似文献
5.
Bortz M.L. Field S.J. Fejer M.M. Nam D.W. Waarts R.G. Welch D.F. 《Quantum Electronics, IEEE Journal of》1994,30(12):2953-2960
We report the demonstration of dimensional noncritical phase matching, a phase-matched interaction length exceeding 10 mm, and an internal conversion efficiency of 204%/W for second harmonic generation of 976 nm radiation in a periodically poled, annealed proton-exchanged LiNbO3 waveguide. Using models for the linear and nonlinear optical properties of annealed proton-exchanged LiNbO3 waveguides and the observed ferroelectric domain grating, the phase-matching wavelength was predicted to within several nm and the conversion efficiency to within ≈20% of the measured values. Optimization of waveguide second harmonic generation devices is discussed 相似文献
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为了获得1.5μm波段可调谐红外光输出,采用短脉冲电场极化法,在1mm厚的掺镁(摩尔分数为0.05)铌酸锂晶体上成功制备了周期为29μm的极化光栅。利用声光调QNd:YVO4固体激光器直接抽运PPMgLN晶体,开展了OPG光学转换研究工作。在输入3W的抽运光时,得到信号光输出功率为44mW,转换效率1.5%。并通过调谐晶体温度(45℃~160℃),获得了调谐范围1.4538μm~1.4750μm的信号光输出。实现了可调谐红外光的输出,验证了晶体周期结构的均匀性。 相似文献
8.
Fonseca-Campos J. Yong Wang Bo Chen Chang-Qing Xu Shiquan Yang Ponomarev E.A. Xiaoyi Bao 《Lightwave Technology, Journal of》2006,24(10):3698-3708
Second-harmonic generation (SHG) of 40-GHz picosecond optical pulses with different pulsewidths, pulse energies, and central wavelengths in a MgO-doped periodically poled lithium niobate (PPLN) waveguide is studied experimentally and theoretically. In the experiments, the picosecond pulses are generated from a 40-GHz mode-locked fiber laser and two tunable filters, with which the lasing wavelength can be tuned from 1530 to 1570 nm, and the pulsewidth can be tuned from 2 to 7 ps. The second-harmonic (SH) pulses are generated when the picosecond pump pulses pass through the MgO-doped PPLN waveguide. Dependences of SHG on pump pulsewidth, average pump power, and pump central wavelength are then investigated systematically. Meanwhile, dynamic behaviors of both pump and SH pulses in propagation are simulated numerically. Based on the temporal and spectral characteristics of SHG, a quantitative and systematic analysis on SHG efficiencies in terms of both pulse energy and spectral peak is presented. The simulation results are in good agreement with the measured data. 相似文献
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A periodically poled structure with 6.95 /spl mu/m period and 10 mm interaction length was fabricated in a 1 mm-thick 1.8 mol% MgO doped near-stoichiometric LiNbO/sub 3/ (MgSLN) by using a multi-pulse poling technique. Blue SHG characteristics of this periodically poled MgSLN were investigated, in comparison with a periodically poled 5 mol% MgO doped congruent LiNbO/sub 3/. 相似文献
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By using a short-pulse field, periodically poled grating (A = 29 μm) was successfully fabricated in a 1.0 mm-thick MgO:LiNbO3 (mole fraction of doped MgO is 5%). A high-repetition-rate optical parametric generation (OPG) based on periodically poled MgO:LiNbO3 (PPMgLN) was pumped by a 1.064 μm acoustooptically Q-switched Nd:YVO4 laser. With 3 W of input pump power, 44 mW of output signal power was obtained at a conversion efficiency of 1.5%. Tunable infrared (IR) output from 1.4538-1.4750 μm was also obtained by tuning the temperature of PPMgLN, which is 45℃-160℃. 相似文献
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Pun E.Y.B. Wong K.K. Andonovic I. Laybourn P.J.R. de la Rue R.M. 《Electronics letters》1982,18(17):740-742
An efficient Bragg-deflection grating on x-cut LiNbO3, using proton exchange in benzoic acid through an aluminium grating mask, has been demonstrated. A deflection efficiency of 90% has been measured. 相似文献
15.
通过对MgO:LiNbO3参量过程温度相位匹配及走离角,允许参量等运转参数的理论计算与分析,确定了晶体的切割角度θ=82℃,以近非临界相位匹配(NCPM)取代NCPM,将温度调节范围控制在较低的温度上,研制了532nm泵浦的MgO:LiNbO3温度调谐脉冲光学参数振荡器(OPO),在800~1700nm波段实现连续调谐输出。参量泵浦功率密度阈值为57.3MW/cm^2,泵浦能量约2倍阈值处,单谐振(SRO)参量转换效率为11%以上。 相似文献
16.
一种宽带低啁啾z切Ti∶LiNbO3调制器 总被引:1,自引:1,他引:0
对正常型和反转极化型LiNbO3波导在任意方向加电场,由线性电光效应引起的折射率的变化做了计算分析,结果发现只有在z方向加电场,LiNbO3两波导臂折射率的变化才是完全相反的.实验验证得到了同样结论.提出一种利用反转技术、厚电极制作和脊型结构的新型宽带低啁啾的LiNbO3调制器.计算结果表明,在实现光波和微波速度匹配情况下,当器件的微波损耗系数为0.15
dB/(cm·√GHz),以及正常型和反转极化型LiNbO3波导长度相等时,其频率啁啾参数非常小,40
GHz时约为0.1. 相似文献
17.
Theoretical analysis of second-harmonic generation (SHG) phase matched with gratings in a channel waveguide is presented from the viewpoint of device design. The analysis includes cases where efficiency is high and residual phase mismatch is involved. Nonlinear couples mode equations, with general expressions for effective SHG coefficients and coupling coefficients, are derived, solved, and discussed for uniform and chirped gratings. It was found that very high efficiency with broadened phase matching bandwidth can be simultaneously obtained with chirped gratings. The results are summarized in graphic data with normalized parameters, and guidelines and criterion for optimum design are given 相似文献
18.
Phase-matched second-harmonic generation by mode conversion in a new waveguide structure fabricated by the Langmuir-Blodgett (LB) technique is demonstrated. The nonlinear optically active part of the waveguide consists of two LB layers with opposite sign to the nonlinear optical coefficient d/sub 33/. This configuration leads to a large improvement of the overlap integral as compared to conventional waveguides. In first experiments conversion efficiencies up to 1%W/sup -1/cm/sup -2/ have been obtained.<> 相似文献
19.
We have achieved a single-mode fibre to waveguide to fibre total insertion loss as low as 1 dB for a 1 cm-long titanium-diffused lithium niobate waveguide. 相似文献
20.
Waveguide quasi-phase matching second-harmonic generation (QPM-SHG) using an organic molecular crystal as a nonlinear material was demonstrated for the first time. The device is constructed with an array of SiN channel guides with grooves of a fan-out grating pattern and mNA single crystal grown over the waveguides. A normalized efficiency of 0.04%/W was obtained in an experiment involving frequency doubling of CW Nd:YAG laser light 相似文献