We explore synchronization dynamics of dual-polarization solid-state lasers. Such lasers are able to produce a stable beat frequency in a wide range from Hz up to THz. This work take advantage of it in order to study several frequency locking mecanisms in these lasers. First, we build a dual-polarization laser with a semiconductor saturable absorber miror (SESAM). It enable a pulsed operation of the laser where all longitudinal modes are phase-locked, and this on both laser eigenstates. We also demonstrate that polarization state of successive pulses forms sequences that we describes here. A particular phenomenon is observed in this laser: when the beat-frequency is chosen equal to half the free spectral range of the laser, then the two frequency combs associated with the two laser eigenstates synchronize themself. Second, we submit a two-frequency laser to a frequency-shifted feedback. Doing so, we are able to transfer the radiofrequency synthetizer stability on the laser beat-frequency. This result is obtained both in cw and Q-switched regimes. Finally, together with the frequency-shifted feedback, we use the relaxation oscillations of a class B laser to induce a regime where the laser beat-frequency is synchronized with the external reference, while their relative phase oscillates. Subsequently, particular intensity dynamics are observed at the output.
