Modal discrimination in leaky-mode (antiguided) arrays (diode lasers)

Presents on the fabrication of a ten-element antiguided (leaky-mode) diode laser array that operates in an in-phase mode with a diffraction-limited far-field pattern at drive currents up to 8.7 times the threshold current (pulsed) and an output power of 400 mW (both facets). This device evidences good discrimination against the out-of-phase leaky mode without the benefit of a 'Talbot' spatial filter, relying instead on mode-sensitive interelement losses in an overlying GaAs layer. This device has been studied using two numerical models. Results from the more realistic of the two models predict in-phase-mode operation for certain restricted ranges of waveguide dielectric constant, in agreement with experiment. This behavior is shown to result from resonances between the waveguide modes and the modes of the active region. These results suggest that improved yields would result from a different type of leaky-mode array employing smaller, rectangularly shaped waveguides.<
>