This paper shows that waveguides induced by grey screening-photovoltaic solitons are always single mode for all intensity ratio, which are the ratio between the peak intensity of the soliton and the dark irradiance. It finds that the confined energy near the centre of the grey soliton and the propagation constant of the guided mode increase monotonically with increasing intensity ratio. On the other hand, when the soliton greyness increases, the confined energy near the centre of the grey soliton and the propagation constant of the guided mode reduce monotonically.When the bulk photovoltaic effect is neglected for short circits, these waveguidesd become waveguides induced by grey screening solitons.When the exteal bias field is absent, these waveguides become waveguides induced by grey photovoltaic solitons.