Mode Selection in Disordered Media by External Magnetic Field Modulation
H. Liu, L-M. Leng, H-L. Ma and S. Zhang
The laser action in one-dimensional (1-D) disordered media composed of magnetically active semiconductor material is investigated by simultaneously solving Maxwell’s equations and rate equations of electronic population. An analysis model is proposed to explain that emission spectrum from the semiconductor-based disordered media can be tunable by external magnetic fields. The dielectric constant of the semiconductor would be modified in different frequency ranges due to the magneto-optical Voigt effect which has significant influence on the laser action. Results indicate that the threshold characteristics can be externally controlled by varying the external magnetic field and pump profile, which provides an effective mode selection method in disordered media.
Keywords: Laser beam mode, disordered media, magnetic field modulation, nonlinear optics, Maxwell’s equation, frequency-dependant time-domain (FDTD) model, magneto-optical effects, Voigt effect