The present invention relates to an apparatus for making a source material into a crystal fiber having different regions of polarization inversion. The apparatus of the present invention is similar to a laser-heated pedestal growth (LHPG) apparatus, characterized in that a first electric field generating device and a second electric field generating device are included. The first electric field generating device is used for providing a first external electric field which is used for poling the crystal fiber and inducing micro-swing of the crystal fiber. The second electric field generating device is disposed on a predetermined position above the first electric field generating device for providing a second external electric field to control and maintain the amplitude of the micro-swing. Whereby, the growth condition of the crystal fiber can be controlled precisely, and a uniformly and regularly periodic polarization inversion structure is fabricated.