On the soliton generation in optical fibres

The author comments on a paper by Burzlaff (see ibid., vol.21, p.561 (1988)). His paper is devoted to the investigation of optical soliton generation for special input pulses within the framework of the non-linear Schrodinger equation. The author demonstrates that the main result by Burzlaff, namely the threshold condition for soliton generation, may be obtained in a general form for any initial pulse with a constant phase (and its Galilei transformation). In particular, the author's general result includes the Burzlaff results. The author notes also that the formula obtained is applicable to the sine-Gordon equation with a special type of initial condition.