Laser à semi-conducteur III-V à émission verticale de haute cohérence et de forte puissance : Etat vortex, continuum et bifréquence THz

摘要

The work presented in this thesis focuses on the design, implementation and physical study of new laser sources of high power and high consistency of emitting photons states "exotic" other than the single-frequency regime conventional TEM 00. The new quasi-coherent states we were able to demonstrate concern on the one hand the transverse aspect of the wave, with the generation of higher order transverse modes in the base of Laguerre-Gaussian (LG) degenerate or non-degenerate ( optical vortex), and in the other hand, for the longitudinal aspect with a so-called "modeless" laser, with a broadband and cohérent spectrum. For these demonstrations, laser technologies VECSEL was the choise of the study by exploiting the GaAs materials industry.The interest of the VECSEL technology is the combination of an optically stable cavity in free space to a low thickness gain. Thus, it is possible to integrate metal filters (nm thickness) or phase filters (based on a photonic crystal) directly on the semiconductor chip, to structure the laser mode. This has been demonstrated experimentally by performing VECSEL source emitting a single spatial mode of higher order and controlled, caught in the LG base.For the longitudinal aspect of the wave, the introduction of a spectral shift element into the cavity allows the realization of a frequency shifted feedback laser, whose emission spectrum is wide (1 nm), and "chirped" with a deterministic relationship between its spectral components. This type of laser source is of growing interest both for understanding the nature of the emitted field and for potential applications in the field of optoelectronics.