共查询到19条相似文献,搜索用时 281 毫秒
1.
2.
3.
利用相干布居振荡技术在介质吸收光谱上产生烧孔,孔宽大约为基态粒子数恢复时间的倒数. 由增益理论分析得到不同抽运光功率对介质吸收状态的影响. 在介质的吸收区域,振荡导致光脉冲经历饱和吸收,脉冲传输延迟;在介质的增益区域,振荡又导致光脉冲经历增益饱和,脉冲传输超前. 应用此技术在掺铒光纤中实现了光速人为可控. 在掺铒光纤晶体中观测到了最慢为2.857×103m/s的光速减慢传输,相应感生群折射率为10.5×104. 根据布居振荡效应及增益理论,由速率方程出发,得到了
关键词:
光谱烧孔
相干布居振荡
饱和吸收
慢光 相似文献
4.
5.
卟啉类有机体系THP/PMMA的永久性光谱烧孔 总被引:3,自引:3,他引:0
首次报道了四-对羟基苯基卟吩/有机玻璃体系(THP/PMMA)的单光子永久性光谱烧孔.研究了烧孔特性和成孔条件.测量了孔的稳定性,在液氦温度下孔的保存时间已超过几个小时.实现了孔的擦除和重复烧孔.探讨了烧孔机制,认为激光诱导质子转位变构是导致该体系永久性光谱烧孔的原因. 相似文献
6.
电光晶体调谐的外腔反馈半导体激光器 总被引:1,自引:0,他引:1
报道一种用电光晶体实现快速调谐和凋制激光频率的方法.在Littrow型外腔反馈半导体激光中插入LiNbO3晶体,利用LiNbO3晶体的电光效应,通过改变晶体电压来调节激光器的有效腔长,可以对激光频率进行快速的调谐和调制.采用该方法,自制外腔反馈半导体激光器的调谐频率可达到2 kHz,它的调谐范围为350 MHz,激光频率调谐系数约为1.06 MHz/V,用饱和吸收光谱观测频率调谐的效果.快速激光频率调制可以应用在稳频技术上,将外腔反馈半导体激光器调制在5~100 kHz频率下,均获得了87Rb原子D2线的饱和吸收光谱的色散信号,并实现了激光频率在饱和吸收峰上的长期稳定. 相似文献
7.
8.
9.
结合声光调制原理和锁定放大器的工作原理,设计了基于调制法的测量光速实验.通过测量和计算得出光速为2.993×108 m/s和3.000×108 m/s,与光在空气中的速度值2.997×108 m/s相比,误差分别为0.13%和0.10%.此方法的优点是光速经过调制后,光的频率被调制为60~100 MHz,使得光波长调制为3~5 m,便于在实验室里进行光速测量. 相似文献
10.
用Monte Carlo方法模拟了强磁场下红宝石中的光谱烧孔过程.假设光学失相完全由晶格Al核自旋的随机跳变引起,并考虑到“冷冻核”效应,较好地解释实验结果. 相似文献
11.
F. Malota 《Optical and Quantum Electronics》1970,2(2):99-101
It has been shown by experiments, that regular relaxation pulses are generated by moving the crystal of a ruby laser. The impulse frequency depend on the velocity of the crystal. 相似文献
12.
We have observed slow light propagation with a group velocity as low as 57.5+/-0.5 m/s at room temperature in a ruby crystal. A quantum coherence effect, coherent population oscillations, produces a very narrow spectral "hole" in the homogeneously broadened absorption profile of ruby. The resulting rapid spectral variation of the refractive index leads to a large value of the group index. We observe slow light propagation both for Gaussian-shaped light pulses and for amplitude modulated optical beams in a system that is much simpler than those previously used for generating slow light. 相似文献
13.
A method of difference frequency generation is suggested for the determination of laser time characteristics. A difference frequency generation in the range from 1.67 to 3.33 cm-1 (with a peak power in the order of 200 mW) has been obtained by means of frequency mixing of two ruby lasers in a LiNbO3 crystal. The generation efficiency dependence on the laser pulses time overlap is investigated. The results obtained experimentally are compared with theoretical calculations. 相似文献
14.
P.E. Oettinger 《Journal of Quantitative Spectroscopy & Radiative Transfer》1977,18(4):369-371
Twenty watts of tunable, pulsed i.r. power in the 6.7–9 μm spectral region were generated from the difference frequency between the outputs from a Q-switched ruby laser and a tunable narrow-bandwidth, near-i.r. dye laser mixed in a 1-mm thick proustite crystal. The i.r. halfwidth was measured to be approx. 0.1 μm. At 10.5 μm, where there is strong absorption of radiation, 5 W of power were recorded. 相似文献
15.
A luminescent trace has been observed in a ruby crystal (Al2O3: Cr3+) that rotates at a frequency of 2 to 200 Hz and is irradiated by 532-nm coherent electromagnetic radiation. A method has been proposed to determine the lifetime of the excited electronic state of chromium ions from the measurement of the length of an arc of the trajectory of a light spot on the surface of a rotating ruby single crystal. A “comet trace” formed at the passage of radiation through the rotating crystal near the absorption band of the material has been detected inside the ruby crystal. It has been shown that the theory based on the analysis of the motion of polaritons in the rotating reference frame is in satisfactory agreement with experimental results. 相似文献
16.
Threshold time and pulsation frequency of a ruby laser are studied experimentally as a function of pumping power. Results are compared with theoretical calculations. The absolute value of the probability of pumping quantum absorption is determined, and the minimal energy introduced into the ruby rod is estimated. It is shown that it is possible to use nonstationary characteristics for determining laser parameters. 相似文献
17.
General expressions for the nonlinear interaction coefficients are obtained for three methods of mixing light waves at uniaxial crystals in the phase matching directions. Comparison of these coefficients enables one to choose the most effective method of mixing waves. Such a comparison is carried out for the generation of the difference frequency at a lithium niobate crystal and of the sum frequency at a KDP crystal in mixing the radiations of ruby and neodymium lasers. 相似文献
18.
Experimental evidence is given that the EPR absorption spectrum of diluted ruby is about 100% homogeneously broadened when observed with the external field H perpendicular to the ruby crystal axis, while it is inhomogeneously broadened, with well defined spin packets, when observed with H parallel to the ruby crystal axis. Relation to ENDOR and spin-echo experiments is discussed. 相似文献
19.
We have theoretically studied the modal dispersion characteristics, group velocity, and effective group as well as phase index of refraction of ternary one-dimensional (1D) plasma photonic band gap (PBG) structure having periodic multilayers of three different materials in one unit cell. The dispersion characteristics related for such structure is derived by solving Maxwell wave equation based on principle of Kronig-Penny model. From the computed results we observe that the dispersion characteristics of such structure also show the frequency gap and cutoffs as found in (binary) one-dimensional plasma photonic crystal. The frequency gap is shown to become larger with the increase of plasma frequency as well as plasma width. It is seen that such structure provide additional degree of freedom to control dispersion characteristic, group velocity and effective index of refraction compared to conventional one-dimensional plasma photonic crystal. 相似文献