共查询到20条相似文献,搜索用时 0 毫秒
1.
Bernier M Faucher D Vallée R Saliminia A Androz G Sheng Y Chin SL 《Optics letters》2007,32(5):454-456
Fiber Bragg gratings were written in thulium-doped and undoped single-mode ZBLAN fibers by focusing femtosecond laser pulses on the fiber core through a phase mask. Maximum index modulation of the order of 1 x 10(-3) was induced in both types of fibers. Measurements of the transverse refractive index changes across the core and cladding regions indicate that the grating formation originates from a negative index change. 相似文献
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A femtosecond optical parametric oscillator synchronously pumped by a Ti:Sapphire oscillator is reported. By the cavity length
tuning, the signal wavelength is continuously tuned from 1000 to 1200 nm. The average output power of 32 mW is obtained at
1053 nm. The pulse width is measured to be 342 fs by intensity autocorrelation method. In addition, we observed bichromatic
emission during the cavity length tuning process.
Supported by the National High Technology Program Research and Development Program of China, the National Natural Science
Foundation of China (Grant Nos. 60490280 and 10804128), and the National Basic Research Program of China (Grant No. 2007CB815104) 相似文献
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利用800 nm飞秒激光脉冲作为光源,在标准通信单模光纤上直接刻写周期分别为100,200,300和400 m的长周期光纤光栅(LPFG),得到波长范围为1 280~1 680 nm的透射谱,分析研究了在不同刻写条件下LPFG透射谱的共振波长、透射深度和插入损耗等参数的变化。通过对比分析发现透射衰减与刻写长度、条数以及平台高度等有着一定的对应关系。优化实验参数制作出共振波长分别约为1 407,1 311,1 669,1 551 nm,透射深度分别约为24.0,22.3,27.8,23.4 dB,插入损耗分别约为2.5,1.7,3.2,2.0 dB的LPFG。 相似文献
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The spectral resolved femtosecond pump-probe experiment is applied to measure the third order nonlinear refractive index coefficient, two-photon absorption coefficient of GaP crystal, and the chirp parameter of the input laser pulses. The results show that nonlinear refractive index coefficient is 2× 10-18 m2/W, twophoton absorption coefficient is 2× 10-11 m/W at wavelength of 783.5 nm, and the chirp parameter of laser pulse is l× 1025 s-2. Furthermore, the mechanism of nonlinear refraction due to two-photon absorption in GaP crystal and experimental results are discussed. 相似文献
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本文分析了小信号情况下飞秒脉冲的倍频特性,在非耗尽近似下,得出了飞秒脉冲二次谐波波形及效率的解析解,在时间域内,对一般条件的耦合波方程进行了数值解,分析了相位失配对飞秒脉冲倍频波形及效率的影响。 用0.5mm厚的一类匹配LBO晶体对碰撞锁模激光器产生的80fs超短脉冲进行了腔外倍频实验,实验结果与理论计算符合得很好。 相似文献
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We demonstrate simultaneous measurement of the real and the imaginary parts of third-order susceptibilities by use of a collinear pump-probe technique. This technique allows for good results and simple implementation. The signal analysis is based on the particular oscillatory signature versus the pump-probe delay allowed by the collinear configuration. Results are compared with interferometric measurements of a SF59 (Schott) glass sample. 相似文献
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We demonstrate a harmonically pumped femtosecond optical parametric oscillator(OPO)laser using a frequency-doubled mode-locked Yb:KGW laser at a repetition rate of 75.5 MHz as the pump laser.Based on a bismuth borate nonlinear crystal,repetition rates up to 1.13 GHz are realized,which is 15 times that of the pump laser.The signal wavelength is tunable from 700 nm to 887 nm.The maximum power of the signal is 207 m W at the central wavelength of 750 nm and the shortest pulse duration is 117 fs at 780 nm.The beam quality(M^2 factor)in the horizontal and vertical directions of the output beam are 1.077 and 1.141,respectively. 相似文献
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Visible continuum generation in air-silica microstructure optical fibers with anomalous dispersion at 800 nm 总被引:26,自引:0,他引:26
We demonstrate experimentally for what is to our knowledge the first time that air-silica microstructure optical fibers can exhibit anomalous dispersion at visible wavelengths. We exploit this feature to generate an optical continuum 550 THz in width, extending from the violet to the infrared, by propagating pulses of 100-fs duration and kilowatt peak powers through a microstructure fiber near the zero-dispersion wavelength. 相似文献
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The third harmonic generation(THG) of a linear cavity Ti:sapphire regenerative amplifier by use of a K_3B_6O_(10)Cl(KBOC) crystal is studied for the first time. Output power up to 5.9 mW is obtained at a central wavelength of 263 nm,corresponding to a conversion efficiency of 4.5% to the second harmonic power. Our results show a tremendous potential for nonlinear frequency conversion into the deep ultraviolet range with the new crystal and the output laser power can be further improved. 相似文献
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Micro-deposition of an aluminum film of 500-nm thickness on a quartz substrate was demonstrated by laserinduced forward transfer (LIFT) using a femtosecond laser pulse. With the help of atomic force microscopy (AFM) and scanning electron microscopy (SEM), the dependence of the morphology of deposited aluminum film on the irradiated laser pulse energy was investigated. As the laser fluence was slightly above the threshold fluence, the higher pressure of plasma for the thicker film made the free surface of solid phase burst out, which resulted in that not only the solid material was sputtered but also the deposited film in the liquid state was made irregularly. 相似文献
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The performance and efficiency of erbium-doped fibers pumped in the 800-nm band has been analyzed using a quantitative amplifier model. Both a silica and a fluorophosphate host were investigated. The analysis showed that under optimized conditions the fluorophosphate is superior to the silica with higher gain and up to 60% higher quantum conversion efficiency. Only with respect to noise figure is the fluorophosphate poorer because of the shorter lifetime of the metastable state. 相似文献
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Viaceslav Kudriasov Valdas Sirutkaitis David N. Nikogosyan 《Optics Communications》2007,271(2):408-412
We investigated UV absorption changes induced in 3.5 mol% Ge-doped fused silica at high-intensity (∼1011-1013 W/cm2) femtosecond (130 fs) irradiation at 267, 400 and 800 nm. We have shown that the induced spectra in the region 190-300 nm are similar in all three cases. At 800 nm irradiation, in addition to the UV absorption changes, we observed small-scale damage due to self-focusing. This damage appears when the incident pulse fluence value of about 1 J/cm2 (pulse intensity of about 7.5 × 1012 W/cm2) is overcome, while the threshold for the induced absorption changes is twice lower. 相似文献
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A pulse compressor has been designed using a 13 mm highly nonlinear photonic crystal fiber to compress pulses centered at 1065 nm from 28 fs to 1.8 fs with a compression factor of 16.2. This compression is achieved by using a high level of energy and generating different orders of solitons without resorting to large values of fiber's dispersion. 相似文献
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A. S. Moskalenko D. A. Rok S. Ya. Umanskii 《Russian Journal of Physical Chemistry B, Focus on Physics》2011,5(1):8-15
For a model molecular system with one vibrational degree of freedom and three electronic states coupled by pump and probe
laser pulses in a condensed medium, the response signal in a femtosecond pump-probe experiment is calculated. The potential
curves of all three states are described by the Morse potential. Calculations are performed using two qualitatively different
approaches to describing the medium-induced relaxation: with memory of the relaxation process and without memory (Markovian
approximation). The temporal evolution of the vibrational wave packet in the intermediate electronically excited state is
described using a master equation for the density matrix of the molecular system, which is derived within the framework of
the Nakajima-Zwanzig formalism. It is demonstrated that, at short delay times, when the proposed approach is applicable, taking
into account memory effects can substantially change the form of the pump-probe experiment signal in comparison with the signal
calculated in the Markovian approximation. 相似文献