Effects of inhomogeneous broadening on optical bistability in a fabry-perot cavity

Dispersive optical bistability in a Fabry-Perot cavity is studied when the atomic transitions are inhomogeneously (Doppler and lorentzian) broadened. Exact numerical results are presented for both the steady state and the transient regimes. In the former case and for Doppler broadening, the atomic inversion shows “two-hole burning” into its velocity distribution. As the Doppler width increases, the bistability parameter has to be increased too in order to regain bistability as found in the ring cavity model. In the lorentzian case the bistable region tends to obliterate more markedly compared with the Doppler counterpart. In the transient regime, it is possible to generate thermal pulses by changing the temperature-dependent Doppler width harmonically with time. Hysteresis cycles are also generated with gaussian pulses. Multiple-valued behaviour of the transmitted light is exhibited in the Fabry-Perot cavity with inclusion of Doppler broadening.     

The correlation of inhomogeneous broadening and the efficiency of data locking in optical echo processors

The formation of responses of stimulated photon echo and the efficiency of data locking under the action of a spatially inhomogeneous electric field on a resonance medium are analyzed. It is shown that the action of a spatially inhomogeneous electric field on a resonance medium between the first and second excitation laser pulses leads to the reversible destruction of the phase memory of the medium, which manifests itself in a change in the time-frequency correlation of inhomogeneous broadening. The possibility of controlling the efficiency of data locking by varying the gradient of an external nonuniform electric field is considered.     

Observation of inhomogeneous spectral broadening of stimulated brillouin scattering in an optical fiber

We report experimental results which show that the stimulated Brillouin scattering (SBS) spectrum in an optical fiber is inhomogeneous, exhibiting spectral broadening and hole burning under cw monochromatic laser excitation. This phenomenon arises from the waveguide interaction of the pump and Stokes signals and is a fundamental property of SBS in waveguiding systems due to their ability to confine a fan of radiation wave vector directions.     

非均匀光纤中梯度项对模式的影响

对弱导非均匀折射率分布光纤的严格理论分析表明,显然在纵向场分量的标量波动方程中能够保留▽δ梯度项,但同时在横向场分量的方程中必须略去梯度项.并以TM模为例,给出了梯度项影响的具体表达式;消除了TM与TE模式之间的简并,明确了单模工作条件.     

The influence of coordinated defects on inhomogeneous broadening in cubic lattices

The joint probability distribution function (JPDF) of electric field gradient (EFG) tensor components in cubic materials is dominated by coordinated pairings of defects in shells near probe nuclei. The contributions from these inner shell combinations and their surrounding structures contain the essential physics that determine the PAC-relevant quantities derived from them. The JPDF can be used to predict the nature of inhomogeneous broadening (IHB) in perturbed angular correlation (PAC) experiments by modeling the G ₂ spectrum and finding expectation values for V _zz and η. The ease with which this can be done depends upon the representation of the JPDF. Expanding on an earlier work by Czjzek et al. (Hyperfine Interact. 14, 189–194, 1983), Evenson et al. (Hyperfine Interact. 237, 119, 2016) provide a set of coordinates constructed from the EFG tensor invariants they named W ₁ and W ₂. Using this parameterization, the JPDF in cubic structures was constructed using a point charge model in which a single trapped defect (TD) is the nearest neighbor to a probe nucleus. Individual defects on nearby lattice sites pair with the TD to provide a locus of points in the W ₁?W ₂ plane around which an amorphous-like distribution of probability density grows. Interestingly, however, marginal, separable PDFs appear adequate to model IHB relevant cases. We present cases from simulations in cubic materials illustrating the importance of these near-shell coordinations.     

The effects of inhomogeneous broadening in an organic microcavity laser

In this work we study the input–output characteristics of an organic vertical cavity surface emitting laser (OVCSEL) with an active layer of Alq3:DCM over 3 orders of magnitude in pump intensity. We find that lasing from this standard inhomogeneously broadened gain medium cannot be described using a single lasing threshold value. Instead, an inhomogeneously broadened distribution of spontaneous emission factors, beta, must be employed in order to correctly model the measured input–output characteristics.     

Coherent control of optical transient processes in a gas

The possibility of controlling the processes of the free-polarization decay and photon echo in a gas by means of resonant CW radiation has been shown. The photon echo and free-polarization decay are formed using the method of the Stark switching of levels in a low-intensity radiation field in the presence of an orthogonally polarized strong field. The experiments in the gas at the R(4, 3) transition in the vibrational band 0 ? 1 v₃ ¹³CH₃F in the presence of radiation from a CW CO₂ laser and the calculations by the evolution operator method show a strong effect of the high-intensity radiation field on the photon echo and free-polarization decay to its complete suppression.     

Anisotropy of inhomogeneous resonant media during transient interaction with optical pulses

This study predicts the manifestation of anisotropic properties in linearly isotropic inhomogeneous resonant media during the propagation of optical pulses through them with pulse durations comparable to the phase memory of the medium. For examples, the energy of an obliquely incident pulse propagating through a layered inhomogeneous medium, varies with inversion of the propagation direction. This effect results from phase modulation of the pulse duse to variation in refraction in a region of transient coherent processes in the medium. This study analyzes the most favorable conditions for observing anisotropic effects.V. D. Kuznetsov Siberian Physical — Technical Institute, Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 96–99, August, 1994.     

Effects of inhomogeneous broadening on two-frequency longitudinal wiggler brightness

The two-frequency longitudinal wiggler brightness is further extended to include the effects of betatron oscillations. The analytic expressions and the results with relevant physical consequences are presented for a comparison with the linear two-frequency undulator field, a popular device proposed earlier for side band suppression and quasi-continuous behaviour.     

基于瞬态光克尔效应的超快光学快门技术

系统介绍了几种基于瞬态光克尔效应的超快光学快门技术,包括传统的光克尔双折射快门技术,瞬态光栅快门技术,以及利用瞬态克尔透镜效应的光学快门技术。这些技术都是在泵浦-探测的实验配置基础上,利用门控光对克尔介质折射率的瞬态调制导致的信号光的相位（偏振态）、传播方向或光束发散角等光学特性的改变实现对信号光的超快时间分辨测量。对比讨论了这些超快快门技术的工作原理和实验配置,结果表明瞬态光束偏折快门技术相比其他快门技术具有无偏振配置要求、无相位匹配条件、超宽带光谱响应范围的特点,在光与物质相互作用的超快动力学研究中具有更为广阔的应用前景。     

Femtosecond optical second harmonic generation by metal clusters: The influence of inhomogeneous line broadening on the dephasing time of surface plasmon excitation

Received: 4 December 1998     

Estimate of inhomogeneous line broadening in steady-state magnetic resonance

We have established relationships between the experimental and theoretical absorption and dispersion line parameters for steady-state magnetic resonance, allowing us to determine both the field characteristics (amplitude of the a.c. magnetic field) and the relaxation characteristics (longitudinal and transverse relaxation times) of the object under study.     

The effect of Doppler broadening on dispersive and absorptive properties in atomic systems with two-photon interference

The effect of Doppler broadening on dispersive and absorptive properties is theoretically investigated in the hot four-level electromagnetically induced transparency (EIT) atomic systems with two different types of two-photon interference. It is found that the dispersive behavior for the probe in the ladder-type atomic system with two-photon constructive interference will be changed from anomalous in cold atoms to normal in hot atoms, and the three-peak absorptive profile is shifted to a broadened spectrum with a shallow dip at the line center; as a comparison, there is always normal dispersion at the line center for the invert-Y-type atomic system with two-photon destructive interference, but the EIT window in the absorptive profile will be narrowed to subnatural linewidth (0.01Γ) at room temperature. The physics of those two different behaviors are discussed and compared in the dressed-state theory.     

The effect of determined chaos on light collection in optical systems

In terms of the dynamic approach, the collection of light in optical systems and the influence of determined chaos on the photometry and fluctuations of regular and chaotic collection are considered. The photometric relationships generalizing the formula of the integrating sphere as applied to chaotic collection are obtained. A universal law for noise in the regular light collection is predicted and found to be in good agreement with the available experimental data. The relationships studied can find use in the elaboration of a new-design detectors, light guides, light-emitting diodes, etc., for the enhancement of their efficiency and the reduction of noise.     

Molecular Stark effect spectroscopy of diflavonol and inhomogeneous broadening of its electronic spectra in erythrocyte membranes

Using spectroscopy of the molecular Stark effect and fluorescence spectroscopy, we study the characteristics of diflavonol 3,7-dihydroxy-2,8-di(4-dimethylaminophenyl)-4H,6H-pyrano[3,2-g]chromene-4,6-dione (DFME), which demonstrates intramolecular charge and proton phototransfer. In the ground state, this dye has only one form and, in the excited state, it has two forms, i.e., normal and phototautomeric. We found that, for the normal form of DFME, the transition dipole moment that is responsible for the absorption (m _a ), the dipole moment in the equilibrium ground state (μ _g ), and the change of the dipole moment upon transition of the molecule in the excited Franck-Condon state (Δ ^a μ) are parallel. In the ground equilibrium state, the dipole moments in 1,4-dioxane and cyclohexane are equal to μg = 12.2 × 10⁻³⁰ C m and μ _g = 11.0 × 10⁻³⁰ C m, respectively. Upon excitation, they increase by Δ ^a μ = 61 × 10⁻³⁰ C m and Δ ^a μ = 50.2 × 10⁻³⁰ C m in these solvents. We study the spectral characteristics of DFME in organic solvents and erythrocyte membranes. A spectral inhomogeneity of DFME in erythrocyte ghosts is found. The inhomogeneous broadening of fluorescence spectra is manifested as a long-wavelength shift of the band of the normal form of DFME by 1640 cm⁻¹ upon excitation at the red edge of the absorption spectrum.