MODAL-ANALYSIS OF POLARIZATION SELF-MODULATED LASERS

The eigenstate spectrum of polarization self-modulated lasers is theor etically and experimentally investigated. The polarizations and freque ncies of the eigenstates of such lasers are theoretically derived in t he framework of the Jones matrix formalism by assuming the self-consis tency of the field after one round trip through the cavity. The result ing predictions are successfully checked experimentally as well in the case of a polarization self-modulated multimode gas laser as in the c ase of st polarization self-modulated external-cavity semiconductor la ser. In particular, it is shown experimentally that the pulses at a fr equency equal to half the free spectral range observed in such lasers can be interpreted as a beat between the two eigenstates that oscillat e in a single round trip in the cavity. This behavior is shown to be i n agreement with a one round trip operation of the laser. Then, the te mporal properties of such lasers are suggested to be due to the self-m ode-locking between the different eigenstates.