Temporal quantum fluctuations in stimulated Raman scattering: Coherent-modes description

Abstract

Temporal quantum fluctuations of the intensity of light pulses produced in the linear regime of stimulated Raman scattering are observed. A theoretical description based on the concept of coherent temporal modes is presented. The method makes use of a minimum number of random variables, which are the excitation amplitudes of the temporal modes, and allows an estimate of the probability for generating a Stokes pulse that is likely to form a soliton in the nonlinear propagation regime.

Photon wave functions, wave-packet quantization of light, and coherence theory

“…In such a case, Titulaer and Glauber (T-G) showed that one may expand the electric and magnetic fields in terms of non-orthogonal, non-monochromatic, spatial-temporal modes v j, x,t ( ) [7]. Such modes were used to study transient Raman scattering [26], and have been recently discussed in terms of the transverse spatial modes of light [27]. These wave-packet modes are related to the orthogonal, monochromatic, plane-wave modes through the non-unitary transformation v j, x,t ( )= i…”

Photon-matter quantum correlations in spontaneous Raman scattering

“…Raman scattering is one of the most fundamental lightmatter interactions: an incident photon scatters inelastically in a medium, transferring energy to, or gaining energy from, a specific excited state. The lifetime of this excited state, which is finite due to interaction with the environment, dictates the Raman gain spectrum and affects the spatio-temporal structure of the Raman-generated optical field [1][2][3][4] as well as its intensity and fluctuations [1,[5][6][7][8]. The equations of motion for the optical field and medium excitation generated in the Raman interaction have traditionally been solved in the Heisenberg picture, where the temporal decay of the material excitation is taken into account through a dissipationfluctuation mechanism [1,2,8,9].…”

“…The equations of motion for the optical field and medium excitation generated in the Raman interaction have traditionally been solved in the Heisenberg picture, where the temporal decay of the material excitation is taken into account through a dissipationfluctuation mechanism [1,2,8,9]. Using this formalism an extensive body of work has formed around exploration of the quantum properties of the spontaneously-initiated optical field, including the decomposition of the field into independent temporal coherence modes [1,3] and decomposition of the excitation field into corresponding orthonormal spatial modes [4,10]. Here we investigate the quantum correlations (entanglement) between modes of a single Stokes photon and its single material excitation counterpart in the Schrödinger picture, focusing instead on the spectral representation of these modes.…”

Mirrorless parametric oscillation in an atomic Raman process

“…Because of the single-pass nature in these effects, a strong pump is required and is often in pulsed form in order to prepare the active medium for the buildup of the coherent emission. Genuine mirrorless laser operation in Raman processes takes the form of amplified spontaneous emission where the transition from the regime of spontaneous thermal radiation to the regime of coherent stimulated emission occurs as the strong Raman pump intensity increases [38]. This is possible because of the good Raman gains obtained under the strong pulsed Raman pump field.…”