Nonlinear conversion of continuous radiation by stimulatedscattering waveguide lasers
Abstract
A method is proposed for nonlinear conversion of continuous radiation into a periodic sequence of strong pulses, by a stimulatedscattering laser in a fiberoptic waveguide. The theoretical development of this method is based on numerical solution of the corresponding system of nonlinear partial differential equations which describe the dynamics of radiation emission by such a laser, with a noise field already present and a short triggering pulse within the Stokes region of the noise spectrum available. Continuous radiation is assumed to be pumping the laser, led in through the resonator cavity so as to excite waves propagating in one direction only. Under consideration is both stimulated Mandel'shtamBrillouin (SMBS) and Raman (SRS) scattering, only excitation of the first Stokes component in each case being considered as a practical matter. Interaction of the radiation field with intrinsic oscillations of the scattering medium, hypersonic and molecular ones, is described by a system of partial differential equations for slowly varying amplitudes of the pumping radiation wave and the first Stokes component. This system of equations is solved for appropriate boundary conditions in the resonator cavity, assuming that at time t = 0 a rectangular pumping pulse of infinitely long duration appears at the cavity entrance. The performance of such a radiation converter will depend on the ratios of SMBS and SRS gain increments as well as on the delay in excitation of a hypersonic wave in the scattering medium.
 Publication:

USSR Rept Phys Math JPRS UPM
 Pub Date:
 April 1987
 Bibcode:
 1987RpPhM.......22D
 Keywords:

 Boundary Value Problems;
 Fiber Optics;
 Nonlinear Equations;
 Partial Differential Equations;
 Scattering;
 Waveguide Lasers;
 Boundary Conditions;
 Numerical Analysis;
 Optical Waveguides;
 Radiation Distribution;
 Raman Spectra;
 Lasers and Masers