A novel technique for the simultaneous generation of bright and dark soliton trains from continuous wave (CW) light is proposed and demonstrated numerically. It is based on the optical switching characteristics of a nonlinear optical loop mirror (NOLM) through which the CW signal is switched by a pump pulse train at another wavelength by the creation of cross phase modulation induced phase bias between the counter propagating CW components. The transmitted and reflected signals exiting from the NOLM can then evolve, respectively, into bright and dark soliton trains in fibers with the appropriate group velocity dispersion at the signal wavelength. Numerical simulations indicate that the generated solitons can be narrower than the pump pulse and that the repetition rate of the soliton trains can be higher than that of the pump pulses. Moreover, this technique permits the conversion of nearly all of the CW energy into the soliton train energy without generating pulse pedestals.