Vicinity of
the first (second)
zero dispersion wavelength (ZDW) corresponds to the region of the anomalous
group-delay dispersion located on the right (left)
of the pump wavelength.
In the vicinity of the second ZDW the SRS acts contrary to the third-order dispersion (TOD). This enhances the dispersive (not solitonic) part of the spectrum and suppresses the solitonic part of the spectrum.
The propagation in the long fiber does not produce an additional extra spectral broadening in the vicinity of the second ZDW because the SRS action is compensated by the blue-shift due to the TOD action. In the vicinity of the first ZDW the Raman red-shift of the solitonic spectral part is continual.
| energy | pulse width | third-order dispersion (TOD) |
| 0.8 nJ | 50 fs | vicinity of first ZDW |
| 0.8 nJ | 50 fs | vicinity of second ZDW |