Observation of multiple soliton generation mediated by amplification of asymmetries

Abstract

We report the experimental observation of the formation of multiple optical quadratic solitons in a process mediated by the amplification of minute asymmetries in the diffraction properties of the input light. Experiments were conducted in phase-matched second-harmonic generation in a bulk crystal of periodically poled potassium titanyl phosphate pumped at 1064 nm. The different mechanisms that influence the process were investigated numerically, and the pulsed nature of the pump light was found to play a key role in the observed light distributions.

Quadratic spatial solitons

“…14(b). The simulations show that when the radiation is sufficiently intense, radiation along the axis exhibiting the slowest diffraction coalesces into additional solitons, leading to the three soliton pattern along a line [44,45]. Another effect which has been shown to lead to lines of multiple solitons is input beam asymmetry [45].…”

“…The simulations show that when the radiation is sufficiently intense, radiation along the axis exhibiting the slowest diffraction coalesces into additional solitons, leading to the three soliton pattern along a line [44,45]. Another effect which has been shown to lead to lines of multiple solitons is input beam asymmetry [45]. Since the rate of diffraction along a given axis is inversely proportional to the input beam size along that direction, solitons are expected to coalesce out of the radiation cones along the lines of the major axes of elliptical beam inputs.…”

“…13(e). The physics of multi-soliton generation can be easily understood from the simulations [43,45,46]. For fundamental beam excitation, both the fundamental and harmonic oscillate with propagation distance.…”