We demonstrate an approach to obtain the frequency differences from 1 MHz to hundreds of MHz including3-40 MHz, which was a blank range of the frequency difference in the traditional dual frequency lasers. Weemploy an intra-cavity stress birefringence element in an He-Ne laser, and at the same time apply a transversemagnetic field to the laser. The intra-cavity stress birefringence element, which is the window plate or the mirrorsubstrate applied by a force, is used to split a frequency into two; I.e. To make a single-frequency laser outputtingtwo frequencies. Moreover, the transverse magnetic field is used to decrease greatly the mode competition between the two frequencies so that they are able to oscillate simultaneously. The minimum value of magnetic field forefficiently eliminating the mode competition to ensure the two frequencies work together is studied experimentally.The power tuning performance of the two frequencies (o-light and e-light) is investigated.