Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE
Transverse effects in different schemes of inversionless amplification
Inna L. Plastun
Abstract
Propagation of a weak probe optical beam through a three- level medium pumped with a microwave strong beam is numerically studied. Three various schemes of transitions under the conditions providing the amplification of the probe field without inversion are taken to calculate the atomic polarization which enters the paraxial wave equations. Diffraction and self-action of beams due to nonlinear absorption and refraction are properly taken into account. These effects together with linear absorption and refraction form a complex distribution of gain across the beams. As a result the amplified beam acquires ring transverse patterns and slight asymmetry in the frequency characteristics.