共查询到20条相似文献,搜索用时 46 毫秒
1.
WU Shu-dong 《理论物理通讯》2002,38(11)
We have established the master equation for the micromaser with Kerr medium field density operator,studied the spectrum of the micromaser with Kerr medium and analyzed the influence of Kerr effect and the detuning onthe spectrum. In the thermal-atom regime, we find that Kerr effect broadens linewidth D and increases frequency-shiftS, and that the detuning A narrows linewidth D and increases frequency-shift S as a whole. Moreover Kerr effect leadsto oscillatings more rapidly in the resonance peaks, which means that it causes quantum noise. As a whole, with theincrease of cavity-length L, the linewidth D and frequency-shift S gradually increase. 相似文献
2.
建立了含克尔介质微波激射器腔场稳态光子数分布的表达式.研究了在热原子、临界和超 冷原子的方式下微波激射器中原子在稳态时的反转特性. 结果表明:注入的二能级原子在不 同方式下,原子的反转特性不一样. 在热原子方式下,原子在一部分腔长L的区域无反转, 且随原子注入速率的增大,反转区域和反转概率增大. 在临界方式下,原子的反转呈现周期 性的坍塌和复苏现象. 而在冷原子方式下,原子在腔长L的全部区域无反转. 克尔效应和失 谐量使原子的反转概率减小.
关键词:
微波激射器
原子反转
光子统计
克尔效应 相似文献
3.
We have established the master equation for the micromaser with the ultra-cold Λ-type three-level atoms and studied the photon statistics of the micromaser field. We find that as the atoms become colder,the change of the mean photon-number and the normalized standerd deviation become more regular, and their resonance peaks become sharper. For zero-temperature cavity,there are some regins in which the photon statistics are sub-Poissonian.With the increase of the cavity temperature,both the mean photon-number and the normalized standard deviation increase. When the cavity temperature is high enough, the sub-Poissonian property may disappear. 相似文献
4.
Kerr介质中级联三能级原子与压缩相干态相互作用的光子统计演化 总被引:6,自引:0,他引:6
本文研究了存在Kerr介质的高Q腔中压缩相干态与级联三能级原子相互作用的光子统计演化规律,讨论了光场参数、Kerr介质及相干振幅对平均光子数的影响. 相似文献
5.
建立了超冷V型三能级原子注入的微波激射的腔场光子统计的量子理论,研究了原子相干性对光子统计性质的影响.发现腔内原子的发射概率随腔长变化的曲线中存在着共振峰和非共振平台,原子相干性对这些共振峰和非共振平台的绝对大小和相对比例具有灵活的可调性.原子发射概率的这些特点对腔场光子统计产生了直接的影响.平均光子数随腔长变化的曲线中也存在着共振峰和非共振平台;给定腔长,适当调节原子相干参量,可以使光子数分布向大、小光子数两个方向灵活地移动,平均光子数也相应地增加和减少.研究中还发现,适当选取原子相干参量,光子统计在大
关键词:
微波激射
超冷V型三能级原子
原子相干性
光子统计 相似文献
6.
C. Fang-Yen 《Optics Communications》2006,262(2):224-228
Studies of microlasers and micromasers generally assume that at most one atom is present in the resonator and transit times are much shorter than cavity lifetimes. We use quantum trajectory simulations to investigate the behavior of a microlaser/micromaser in which multiple atoms may be present and atom transit times can be comparable to the cavity decay time. Many-atom events are shown to destroy trap state resonances even for a mean intracavity atom number as small as 0.1. Away from trap states, results for mean photon number agree with a single-atom, weak-decay theory. However the variance of the photon number distribution increases relative to micromaser theory by an amount proportional to the product of the interaction time and cavity decay rate. This excess variance is interpreted as resulting from cavity decay during the atomic transit time. 相似文献
7.
We propose a theory that makes it possible to examine both laser and micromaser two-photon light generation. The theory is
based on the Lamb-Scully model, in which two-level atoms have initial coherence. Such an initial state allows for light generation
involving atoms without inversion or even atoms with negative population inversion in the transition. We analyze the conditions
needed for the emergence of squeezed states of the light field. We also show that the photon statistics in lasing is always
classical but that there appears a state of the field squeezed in the phase with maximum photodetection shot-noise suppression.
For a micromaser we find a regime where sub-Poisson light with a shot-noise suppression level of 60% is realized in an inversionless
transition. In another regime, a squeezed state that produces 75% suppression of noise can be generated.
Zh. éksp. Teor. Fiz. 115, 1605–1618 (May 1999) 相似文献
8.
运用全量子理论并结合数值计算方法,研究了克尔介质腔中处于贝尔态的两个全同二能级纠缠原子与双模纠缠相干光场相互作用系统的光子统计特性。讨论了双原子体系的初态、初始光场的平均光子数、双模纠缠相干光场的纠缠程度以及克尔介质与双模光场的耦合强度对光子统计特性的影响。结果表明:忽略克尔介质的作用时,只有当双原子体系的初态为0β1〉或1β1〉时,在一定的条件下才可出现光子的反聚束效应,而当双原子体系的初态为β00〉、1β0〉时,光场在其演化过程中不出现光子的反聚束效应。而当考虑克尔介质的作用时,四种初态下光场演化过程中均有可能出现光子的反聚束效应。光子的反聚束效应出现的次数、时间和深度极其敏感地依赖于初始光场的平均光子数和克尔介质与双模光场的耦合强度,同时也受到双模纠缠光场的纠缠程度的影响。 相似文献
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克尔介质中纠缠光与三能级原子作用的光子统计 总被引:8,自引:2,他引:6
采用求解薛定谔方程和数值计算方法,研究了克尔介质中双模纠缠相干光场与三能级原子相互作用系统的光子统计性质,分析了双模纠缠相干光场的纠缠程度、克尔介质与光场的耦合强度、双模光的平均光子数和原子基态概率幅对光子统计性质的影响。结果表明:双模纠缠相干光场的纠缠程度对光子统计性质没有明显的影响;克尔效应增强使光子统计性质的时闻演化曲线的振荡频率变大、振荡幅度变小;当保持场模1的平均光子数不变而场模2的平均光子数变小时,光子统计性质的时间演化曲线的振荡幅度变大。 相似文献
11.
Casagrande F Ferraro A Lulli A Bonifacio R Solano E Walther H 《Physical review letters》2003,90(18):183601
We propose a realistic scheme for measuring the micromaser linewidth by monitoring the phase diffusion dynamics of the cavity field. Our strategy consists of exciting an initial coherent state with the same photon number distribution as the micromaser steady-state field, singling out a purely diffusive process in the system dynamics. After the injection of a counterfield, measurements of the population statistics of a probe atom allow us to derive the micromaser linewidth in all ranges of the relevant parameters, establishing experimentally the distinctive features of the micromaser spectrum due to the discreteness of the electromagnetic field. 相似文献
12.
研究Kerr介质中,非旋波近似下,一个级联型三能级原子与光场相互作用的二阶相干度的时间演化,讨论了Kerr效应和虚光场效应对场的光子反聚束效应的影响.结果表明,虚光场的影响使系统出现量子噪声;而Kerr介质常量x、共振频率ω的增大及原子-场耦合系数g的减小都将降低原子对激发场的吸收效率,削弱受激辐射场的光子反聚束效应,其中以g的变化对系统的影响最为明显.
关键词:
非旋波近似
Kerr效应
反聚束 相似文献
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14.
Devendra Kumar Mishra 《Optics Communications》2010,283(17):3284-3290
Recently, Prakash and Mishra [J. Phys. B: at. Mol. Opt. Phys., 39, 2291(2006); 40, 2531(2007)] have studied higher order sub-Poissonian photon statistic conditions for non-classicality in the form of general inequalities for expectation values of products of arbitrary powers of photon number and of photon-number fluctuation. It is, therefore, vital to study the generation of these higher order sub-Poissonian photon statistics (phase-insensitive behavior) in a physically realizable medium and their relations to higher order squeezing (phase-sensitive behavior). In the present paper, we study higher order non-classical properties, such as Hong and Mandel squeezing, amplitude-squared squeezing and higher order sub-Poissonian photon statistics, of squeezed Kerr state which is generated by squeezing the output of a Kerr medium whose input is coherent light. Such states can be realized if laser light is sent through an optical fiber and then into a degenerate parametric amplifier. It is established that the squeezed Kerr state can exhibit higher order non-classical properties. 相似文献
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16.
C. Henkel 《The European physical journal. Special topics》2008,160(1):217-224
We perform a calculation of the linewidth of a micromaser, using
the master equation
and the quantum regression approach. A `dephasing' contribution is
identified from pumping processes that conserve the photon number
and do not appear in the photon statistics. We work out examples for
a single-atom maser with a precisely controlled coupling and for a
laser where the interaction time is broadly distributed.
In the latter case, we also assess the convergence of a
recently developed uniform Lindblad approximation to the master
equation; it is relatively slow. 相似文献
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含Kerr介质的Fock态和相干态腔场中耦合双原子辐射谱 总被引:3,自引:3,他引:0
研究了在充满Kerr介质的高Q腔中两个具有偶极-偶极相互作用的二能级原子辐射谱,给出了初始光场为Fock态和相干态时辐射谱的数值结果.讨论了Kerr效应对谱结构的影响.在初始注入光场为较强的相干态时,辐射谱除中心单峰外,两侧各出现一个多峰梳状边带,峰的个数随初始场平均光子数-n的增大而增多,峰间距随Kerr介质与光场的耦合系数X的增大而增大,两个边带则随Xn-的增大逐渐远离. 相似文献