Dual-pump push-pull polarization control using stimulated Brillouin scattering

Abstract

Stimulated Brillouin scattering (SBS) amplification of probe signals is highly polarization dependent. Maximum and minimum gain values are associated with a pair of orthogonal states of polarization (SOP), which are related to the pump SOP. Since the maximum gain is much higher than the minimum, the SOP of the output probe is pulled towards that of the maximum amplification. Polarization pulling is restricted, however, by pump depletion. In this work, a new method is proposed, analyzed and demonstrated for enhanced SBS polarization pulling, using two orthogonal pumps. Here, one pump amplifies one polarization component of the probe wave, and at the same time the other pump attenuates the corresponding orthogonal component, resulting in a push-pull effect. In the undepleted regime and for equal total power, the same degree of pulling is achieved as in the single pump case, but at a significantly less signal gain. Thus, the dual pump technique can provide high pulling efficiency for stronger input signals, deferring the onset of depletion.

A universal optical all-fiber omnipolarizer

“…In this field research moves along three distinct paths: i) the development of linear and nonlinear methods of re-polarization of a partially coherent and initially fully depolarized light with interferometers1, in a random scattering medium4, via propagation in a Kerr medium56789, or even through propagation of a diffracting beam in free space10; ii) the engineering of dissipative polarizers1112131415161718; iii) the design of nonlinear methods of lossless polarization control of fully coherent and depolarized beams1920212223. Polarizers belonging to the first class are based on the coherent suppression of phase noise, which is intimately related to the incoherent nature of light beams.…”

Nonlinear polarization effects in optical fibers: polarization attraction and modulation instability [Invited]

“…In fact, pulling of the signal polarization toward the pump SOP has been theoretically analyzed and experimentally demonstrated in Brillouin amplifiers [65][66][67].…”

Optical flip–flop memory and data packet switching operation based on polarization bistability in a telecommunication optical fiber

“…As opposed to traditional polarizers, which are known to waste 50% of unpolarized light, Heebner et al proposed in 2000 a "universal polarizer" performing repolarization of unpolarized light with 100% efficiency [1]. Subsequently, this phenomenon of polarization attraction or polarization pulling has been the subject of growing interest in optical fiber systems, involving the Raman effect [2][3][4], Brillouin backscattering [5,6], parametric amplification [7,8], and the full-degenerate four-wave mixing process, also called cross-polarization rotation [9][10][11][12][13][14][15][16][17][18][19]. Note that, from a broader perspective, the recent works obtained in a counterpropagating configuration in telecommunication fibers are inherently based on a four-wave interaction, which has been the subject of pioneering studies in the past [20][21][22][23][24][25].…”