Kerr medium

Theoretical treatment of the femtosecond pulse propagation in a bulk Kerr medium with the dispersion of dielectric permittivity was based on the... 

Here we analyze a measurement-assisted generation of a superposition state. This is in line with the intentions of earlier proposals such as preparation by means of continuous photodetection, [Ogawa 1991], or via state reduction in a Mach-Zehnder interferometer containing a Kerr medium, [Gerry 1999], In order to implement the Zeno-limit evolution given by Eq. (85), we assume in the Hamiltonian (63) for simplicity 6 = 0 and the parameter c to be sufficiendy large such that for some detected ancilla state I I o) the condition ( I ol l I o) = 7oo = cos 0 = — c-1 a can be fulfilled. This yields for... 

Figure 1. Time-evolution of the probabilities (analytical results) for vacuum 0) (solid curve) and one-photon state 1) (dotted curve) for the system with Kerr medium described by the Hamiltonian j%(di)2a2. The circle marks denote numerical results. The pulse strength is e = ti/50.

We assume that our system consists of a Kerr medium of the (s + 1 )th-order nonlinearity and a parametric amplifier driven by a series of ultrashort external classical light pulses. Thus, the Hamiltonian describing our system can be written in the interaction picture as... 

The study of self-phase modulation of one wave may not neglect the statistical properties of the quantum phase. The study of statistical properties of the quantum phase in the situation of self-phase modulation of one wave has a long tradition. To the investigation of the propagation in the Kerr medium including the Kerr nonlinear devices, the nonlinear oscillator model has been applied (see Ref. 210 and references cited therein). The work has been reviewed laying the emphasis on properties of the nonlinear phase shift such as a generation of superposition states. 

Finally, we should enquire as to whether or not it is reasonable to expect a linear response in describing the rotational diffusion of dipoles in the presence of a very strong local field, such as presented by the excess electron. The time window of the optical Kerr gate driven by a picosecond laser pulse depends on the relaxation of the molecules of the Kerr medium from an aligned orientation to an isotropic spatial distribution, once the applied optical field is switched off. For many liquids this relaxation time r is the low field limit, namely, the Debye time. We might anticipate an asynunetry in the temporal response 5 (0 of... 

Often the laser medium itself acts as Kerr medium and forms an additional lens inside the laser resonator. This is shown schematically in Fig. 6.23, where the lenses with focal lengths f and /2 are in practice curved mirrors [679]. Without the Ken-lens the resonator is stable if the distance between the two lenses is f - - f2. With the Ken lens this distance has to be modified to /i -h /2 + where the quantity 8... 

An alternative method for the realization of KLM uses the birefringent properties of the Kerr medium, which turns the plane of polarization of the light wave... 

An alternative method for the realization of KLM uses the birefringent properties of the Kerr medium, which turns the plane of polarization of the light wave passing through the Kerr medium. This is illustrated in Fig. 11.23. The incident wave passes through a linear polarizer and is then elliptically polarized by a A/4-plate. The Kerr medium causes a time dependent nonlinear polarization rotation. A A/2-plate and a linear polarizer behind the Ken-medium can be arranged in such a way that the pulse transmission reaches its maximum at the peak of the incident pulse, thus shortening the pulse width [11.55]. This device acts similarly to a passive saturable absorber and is particularly useful for fiber lasers with ultrashort pulses. 

The temporal evolution of the OKE signals in solutions and films of the linear conjugated polynitriles with different m values was observed. As an example, the time-resolved transient optical Kerr signals of PBN with m = 11.8 are presented (Fig. 24). The signal profiles of all samples are approximately symmetric with respect to the delay time, which indicates a primarily pulse width-limited response. To obtain the relaxation time of the Kerr medium we can fit the experimental curve with an exponential function [45,57]. Because the time constants of all samples are all less than the pulse duration, we can only roughly determine that the relaxation time of all samples is shorter than the laser pulse width (165 fs). The ultrafast optical response may be caused by distortion of the ir-electron cloud occurring with the nonresonant excitation [58]. 

See, for example, Khoo, 1. C., and W. Wang. 1991. Effects of side diffractions and phase modulations on phase conjugations in a Kerr medium. IEEE J. Quantum Electron. QE-27 1310, and reference therein. 

Figure 7.2 Optical block diagram of the wide field Kerr-gated microscope. Note the position of the sample (S), the sequence of three matched Cassegrain objectives (COi, CO2 and CO3), polarizers (Pi and P2), the Kerr medium (K) and blocking filters (F). A prism spectrometer (PR) can be inserted into the path of the gated light allowing monitoring of the collective spectral dynamics of objects within the field of view.

Figure 7.3 Light collecting objective and the Kerr-gate assembly of the second generation Rutgers microscope. The only non-reflective components are the nanowire polarizers and the 0.5. mm thick fused silica plate serving as the Kerr medium.

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