Frequency-stable, narrow linewidth oscillation of a 638 nm AlGaInP diode laser has been achieved with an external photorefractive BaTiO3 phase conjugator in a novel configuration. The mechanism of the phase conjugation in this configuration is the stimulated photorefractive backscattering process with the measured phase-conjugate reflectivity of <1.8x10(-3)%. With this new phase-conjugate feedback method, the laser linewidth was reduced to similar to 0.1 nm (within the resolution limit of the spectrum analyzer used) and the oscillation frequency was highly stabilized, while it was impossible with a conventional cat conjugator. (C) 1996 American Institute of Physics.