Abstract

After a π phase shift in the initial Stokes field had been predicted to initiate soliton formation in the depleted pump field during stimulated Raman scattering, a spontaneously generated π phase shift was certainly observed in the actual Stokes wave. Practically, the amplitude of this anomalous pump reversal forming the soliton often varies from shot to shot, and its spatial profile during the stable propagation in the media has not been known so far. Recently, diffractive soliton decay has been theoretically investigated,¹ however, the fluctuating amplitude makes it difficult to observe experimentally the transverse intensity distribution. In this study, we investigated the reversal composed of various transverse modes and its decay due to transverse phase shift using 2-D and semiclassical calculations with a π phase shift in the initial Stokes field. In conclusion, the spatial profile can be explained on the assumption that transverse-mode coupling occurs even in the soliton formation. If multiple-mode reversal should occur with a low-quality pump beam, it would decay rapidly because of the transverse phase shift during propagation.

© 1991 Optical Society of America