New results on some statistical properties of phase modulated laser fields

Hannes Risken

B. Picinbono

Results were recently reported on statistical properties of phase-modulated laser light. A detailed analysis is presented here of random-phase modulation. In particular it is shown that there are two kinds of such modulation: modulation by phase fluctuations, in which the instantaneous phase is a stationary stochastic process, and modulation by phase diffusion in which the phase is a diffusion process with an always increasing variance. In the case of a Gaussian modulation we show that the optical fields in the two preceding cases are very different, and we calculate their coherence functions. This difference can be detected by an interference experiment, but more easily by photon coincidence or intensity-correlation experiments on a beat between a reference beam and the modulated beams. We present a theoretical analysis of such experiments in the two cases of modulation.

Ce Chen, M. Rifani, Jongwhan Cha +2 more

We report measurements of the absorption spectrum for two-photon absorption from a variety of randomly amplitude-modulated laser fields. The fields are generated by modulating the output of a stabilized tunable ring dye laser external to the laser cavity. As such, the field statistical properties are controllable and well characterized. The fields which we have used in this investigation include the real Gaussian field, the complex Gaussian field, and the real Gaussian field with a coherent component. For the last field, an interesting correlation effect is seen when the coherent component is in phase or 90\ifmmode^\circ\else\textdegree\fi{} out of phase with the stochastic component. We have also investigated the effect of partial correlation of the two counterpropagating fields used in the measurements. In all cases we find excellent agreement between the measured absorption spectra and those calculated from the known fourth-order field-correlation functions.

Hannes Risken

Jingzhao Li, Keyin Li, Ge Zhang +2 more

A new method for regulating optical properties of a coaxial cylindrical quantum well using the electric field and intense laser field is investigated in the effective mass approximation. By means of the finite difference method and the correct dressing effect of the confinement potential, the results show that the enhancement and recovery of optical absorption and refractive index change strongly depend on the multifaceted-cooperative regulation of the laser parameter, the electric field strength, the angle between the electric field and polarization direction of laser, and the barrier width. This is promising for the design of a new generation of highly polarization sensitive devices, optical repair equipments and optical phase modulators by adopting the multistage combination of electric and intense laser fields.

L. Mandeļ