光谱烧孔中孔的宽度和深度与烧孔光持续时间的关系

本文由光学Bloch方程出发,讨论了二能级系统光谱烧孔中孔宽和孔深与烧孔激光脉冲持续时间的关系.在强场下短脉冲烧孔中,用π脉冲可以得到足够深且宽度小于稳态值的孔.弱场下,孔深与烧孔时间成指数关系.Bloch方程的修正对上述两种条件下烧孔行为的描述无明显影响.以二能级系统光谱烧孔为基础,讨论了永久性光谱烧孔和光子选通光谱烧孔中孔的行为.     

高信号背景比的持久性偏振光谱烧孔

用偏振光谱方法对有机固体材料频域存贮材料进行单光子和双光子的选通光谱烧孔，获得了高的信号背景（噪声）比（ＳＢＲ）。文章介绍偏振光谱烧孔原理和实验上得到高信号背景比的方法和结果，展示了偏振光谱烧孔技术在高分辨光谱和频域信号存贮应用的良好前景。     

光子选通光谱烧孔的全息检测与图像存贮

报道在有机光子选通光谱烧孔材料苯基四苯并卟啉锌/芳晴系统中，进行全息光谱烧孔和图像存贮的实验结果．实验表明全息烧孔极大地提高了光谱孔的检测灵敏度和信噪比．通过全息光子选通光谱烧孔，成功地进行了光子选通型的频率选择的多幅全息图存贮，得到清晰的图像再现 关键词：     

Narrow optical hole burning and related effects in ruby

We observed a narrow optical hole burning in ruby whose width (FWHM = 107 kHz) is the narrowest of those reported so far in solids. A hole before reaching its steady state which we call transient hole was used on the basis of theoretical analysis of the hole burning. The first observation of optical wiggles and the detection of superhyperfine structures near zero frequency are reported as two new effects related to the narrow optical hole burning.     

Demonstration of conditional quantum phase shift between ions in a solid

Because of their long coherence times, dopant ions have been considered promising candidates for scalable solid state quantum computing. Here we demonstrate a conditional phase shift between two qubits based on an optical transition of europium ions. The demonstration uses ensembles that have been selected from a randomly doped sample using spectral hole burning techniques. The electron dipole-dipole interaction between the ions that usually causes instantaneous spectral diffusion is used to generate the conditional phase shift.     

球形微粒样品室温永久光谱烧孔的动力学过程及多重性研究

利用球粒表面形态共振，实现室温下的永久光谱烧孔，建立理论模型对动力学过程进行分析，据此对实验结果进行拟合，得到有效成孔速率等参数；并对烧孔的多重性进行研究，将这些结果应用于室温频域光信息存贮将有较好的前景。     

强磁场下红宝石中光谱烧孔的模拟

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.     

Implications of spectral hole burning on the manipulation of spatial Goos–Hänchen shift in an atomic cell

We present a new scheme to report on Goos–Hänchen (GH) shift experienced by the Gaussian light beam interacting with an optical cavity filled with four-level sodium atomic medium in the spectral hole burning region with and without Doppler broadening effect. Theoretical atomic density-matrix formalism is employed to obtain the susceptibility of atomic medium while the stationary-phase-theory is used to compute the GH shift in the reflected and transmitted probe beams subjected to control fields. A steep normal slope of dispersion is observed with a maximum and zero probability of transmission and reflection coefficients, respectively, at the regions of the spectral holes burning. In the normal dispersion spectrum at the region of spectral hole burning, positive and negative GH shift is observed, respectively, in the transmitted and reflected light beams. However, at anomalous dispersive regions negative GH shift in the transmission beam and positive GH shift in the reflection beam is observed. The reflection and transmission coefficients as well as the spatial GH shift are the functions of probe detuning, collective phase of control fields, beam incident angle and inverse Doppler broadening effect in the spectral hole burning region. The position and number of spectral holes also depend on the same spectral parametrs as stated above. The study is expected to be useful for optoelectronic devices and optical-clocking applications.     

The impact of nonequilibrium gain in a spectral laser diode model

We describe the inclusion of nonequilibrium gain into a self-consistent 2.5D CW spectral laser diode model and report on the use of this model to investigate the origin of gain compression in a 975 nm high-brightness tapered QW laser diode. Nonequilibrium gain is calculated using a dynamic gain model, which simulates the dynamic relaxation of the quantum well carrier energy distributions under the influence of steady-state electrical and optical excitation. Calculated gain and spontaneous emission spectra are included in the laser model via parameterised look up tables. Both simulated and experimentally measured intracavity spontaneous emission spectra show an increased carrier density and a blue-shift of the gain maximum with increasing bias caused by carrier heating and spectral hole burning. The accurate incorporation of nonequilibrium gain compression is therefore vital for the accurate prediction of the operating characteristics of these devices and for the experimental determination of the active region temperature.     

半导体光放大器亚皮秒量级超快动态特性的研究

通过考虑脉冲频谱的增益色散，提出了一个分析亚皮秒光脉冲在半导体光放大器(SOA)中传输的新思路.分别对超快光脉冲在时域和频域内进行离散化，建立了一个更为合理的传输数值模型.基于该模型，观察到了脉冲频谱的明显漂移，并探讨了漂移量与脉冲载波波长、脉冲能量、脉冲宽度、SOA长度和注入电流等外部条件之间的关系，从理论上解释了文献没有证实的实验结果.同时，基于交叉增益调制原理，利用双光束结构，描述了载流子加热、光谱烧孔效应和双光子吸收等非线性效应引起的增益压缩.理论分析的结果为改善SOA的动态特性提供了指导. 关键词： 半导体光放大器 超快非线性效应 增益色散性     

持久光谱烧孔动力学的理论模型和实验研究

建立了单光子光化烧孔的三能级模型，求解了反映质子转位变构机制的速率方程组，推导了成孔过程的动力学特性，获得了可与实验进行比较的解析解．用时域和频域两种方法测量了ＴＨＰ／ＰＭＭＡ和ＴＭＰ／ＰＭＭＡ薄膜样品光谱烧孔的动力学过程，得到与理论分析一致的规律，并测得了有效成孔速率和成孔时间等参数．这些参数对于评价频域光存贮材料性能有一定意义．     

An inhomogeneous theoretical model for analysis of PbSe quantum-dot-doped fiber amplifier

Optical fiber doped with lead salts quantum dots (QDs) of different radii, has previously been proposed as a wide-band amplifier in the optical communication range. The emission and absorption spectra of QDs are size-dependent. Optical fiber amplifier doped with QDs of different sizes is an inhomogeneous gain medium. This inhomogeneity is the principle of operation of wide-band quantum-dot-doped fiber amplifiers (QDFAs). To study the effects of inhomogeneity such as spectral hole burning on the amplifier behavior, a fiber amplifier with an arbitrary size distribution of QDs is taken into consideration. The light propagation equations and rate equations for the inhomogeneous medium are presented. To investigate the gain spectrum, the amplifier bandwidth and the spectral hole burning effect on the amplifier behavior, the system of governing equations for the steady-state regime of operation are solved and numerical results are presented.     

Optical decoherence and persistent spectral hole burning in Tm:LiNbO3

We report studies of decoherence and spectral hole burning for the 794 nm optical transition of thulium-doped lithium niobate. In addition to transient spectral holes due to the ³H₄ and ³F₄ excited states of Tm³⁺, persistent spectral holes with lifetimes of up to minutes were observed when a magnetic field of a few hundred Gauss was applied. The observed anti-hole structure identified the hole burning mechanism as population storage in the ¹⁶⁹Tm nuclear hyperfine levels. In addition, the magnetic field was effective in suppressing spectral diffusion, increasing the phase memory lifetime from 11 μs at zero field to 23 μs in a field of 320 Gauss applied along the crystal’s c-axis. Coupling between Tm³⁺ and the ⁷Li and ⁹³Nb spins in the host lattice was also observed and a quadrupole shift of 22 kHz was measured for ⁷Li at 1.7 K. A Stark shift of 18 kHz cm/V was measured for the optical transition with the electric field applied parallel to the c-axis.     

基于半导体光放大器四波混频原理的光采样

建立了可研究强超短光脉冲放大特性且包含自由载流子吸收、受激辐射、双光子吸收、光谱烧孔和超快非线性折射效应的半导体光放大器理论模型,用以建立脉冲四波混频模型,并进一步仿真了基于半导体光放大器的光采样过程,重点讨论了自由载流子吸收、双光子吸收效应对采样特性的影响。仿真结果与实验结果相符。     

新型双波长激光增益控制掺铒光纤放大器

掺铒光纤非均匀展宽引起的空间烧孔现象导致单波长激光并不能完全控制放大器增益。提出了一种新颖简单的结构，利用自由光谱范围为26．7nm的法布里－珀罗可调谐滤波器和由长周期光纤光栅制成的波长选择性可调谐的衰减器，有效地调整不同波长处的腔内损耗，可以实现不同强度的双波长激射。由两个不同波长的激光共同承担增益控制的任务，降低了控制激光引起的空间烧孔，同时双波长激射有效地抑制了信号光的弛豫振荡。     

Spectral Hole-Burning of Eu^3＋：Y2SiO5 Crystal at 16 K

By using an Ar^＋ ion laser, a tunable Rh 6G dye laser （linewidth 0.5cm^-1） pumped by the second harmonic of a YAG：Nd laser and a Coherent 899-21 dye laser as light sources and using a monochromator, a phase-locking amplifier and a computer as the data detecting system, we detect the optical properties of Eu^3＋-doped Y2SiO5 crystal. Persistent ,spectral hole burning （PSHB） are observed in the Eu^3＋ ions spectral lines （^5 Do-T Fo transition） in the crystal at the temperature of 16K. For 15mW dye laser burning the crystal for 0.1 s spectral holes with hole width about 80 MHz both at 579.62nm and at 579.82nm are detected and the holes can remain for a long time, more than 10h.     

A theoretical analysis of the effects of erbium ion pair on the dynamics of an optical gain stabilized fiber amplifier

In this paper, the effects of ion-pair formation on the gain dynamics of multi cavity optical automatic gain control erbium doped fiber amplifier is modelled. The inhomogeneous Cabezas simple model is used to write the rate and propagation equations for the active medium. The solution of the governing equations shows that in high concentration of the erbium ions, depending on the pumping rate, the relaxation oscillations are converted to nT-Periodic or even to chaotic behavior. Although the high concentration erbium ion in the optical amplifiers decreases the conversion efficiency and increases the threshold pump power, amplitude of the transient effects is reduced in the multi feedback-loop WDM amplifiers relative to the low concentration erbium ions multi feedback-loop optical amplifiers and ion-pairs, which act as a saturable absorber to compensate the gain tilt caused by the OAGC laser spectral hole burning. The theoretical results are in complete agreement with the previous published experimental results.     

Optical decoherence times and spectral diffusion in an Er-doped optical fiber measured by two-pulse echoes, stimulated photon echoes, and spectral hole burning

Two-pulse and stimulated photon echoes and spectral hole burning were measured on the transition from the lowest component of the ⁴I_15/2 manifold to the lowest component of ⁴I_13/2 of Er³⁺ in a silicate optical fiber at 1.6 K. The two-pulse echo decays gave decoherence times as long as 230 ns for magnetic fields above 2 T. A large field dependent contribution to the homogeneous line width of >2 MHz was found and interpreted in terms of coupling to magnetic tunneling modes (TLS) in the glass. The stimulated echoes measured at 2 T showed spectral diffusion of 0.8 MHz/decade of time between 0.4 and 500 μs. Spectral diffusion in this high field region is attributed to coupling to elastic TLS modes which have a distribution of flip rates in glasses. Time-resolved spectral hole burning at very low field showed stronger spectral diffusion of 5.7 MHz/decade of time, attributed to coupling to magnetic spin-elastic TLS modes.     

Coherent transients observed by Stark switching in ruby having narrow optical hole burning

By using the Stark switching technique we observed new coherent transient signals in ruby at low laser intensities, which are unique in solids where T₁ ? T₂. It was confirmed that the existence of narrow optical hole burning before the switching plays an essential role in giving rise to the signals. The effects of the multiple optical hole burning were also observed in the time domain. Assuming the existence of the holes, the signals can well be interpreted by linear system analysis.     

Controllable broadening of zero-phonon lines by means of the Doppler effect and prospects of using spectral hole burning in optical informatics

An attempt is made to extend the spectacular variant of optical informatics efficient at liquid helium temperature—holography based on zero-phonon lines (ZPLs) and spectral hole burning, including time-and-space-domain holography—to higher temperatures, up to room temperature. At room temperature, both optical and Mössbauer narrow ZPLs exist; however, they do not have the inhomogeneous broadening that transforms a ZPL into a broad band, which is necessary for informatics based on light pulses. The idea of producing a band with an appropriate width from narrow ZPLs by using the Doppler effect is advanced. A variant of experimental realization of this idea by means of a scheme with a rotating disk covered by a layer of a material sensitive to spectral hole burning is considered. Numerical estimates were performed for narrow optical ZPLs and for the yet experimentally unconfirmed Mössbauer ZPL in the visible spectral range (dark blue nuclear light) that corresponds to a transition between the two low-lying levels of the ²²⁹Th isomer. For the narrowest optical ZPLs known at present, with a width of about 100 Hz, the estimates give favorable results, in particular, for prospects of realizing a photoelectrically accumulated stimulated photon echo.