Coherent combining of spectrally broadened fiber lasers.

We demonstrate that fiber lasers spectrally broadened by cross mode coupling can be coherently combined with high efficiency. The spectral broadening that it induces suppresses stimulated Brillouin scattering. Using long cavity length lasers, > 800 m, we induce spectral broadening of > 50 GHz and show mode by mode coherence in the output of four intracavity coupled fiber lasers.

Bistability of pulsating intensities for double-locked laser diodes.

Rate equations for semiconductor lasers subjected to simultaneous near-resonant optical injection and microwave current modulation are examined by combined analytical-numerical bifurcation techniques. Simple qualitative criteria are given for a bistable response. These results compare well with experimental measurements.

Modifying the one-dimensional power-coupling formalism to model a cw Nd:YAG laser.

A lamp-pumped, cw Nd:YAG laser cannot be modeled adequately by the one-dimensional power-coupling formalism without assuming intensity-dependent cavity losses. The source of the intensity dependence has not been determined but may be due to absorption saturation in the gain medium or to aperture and beam profile effects.

Conjugate generation and beam steering by nearly degenerate four-wave mixing in waveguide arrays.

We analyze the frequency-shifted conjugate beam generated by nearly degenerate four-wave mixing in an array of single-mode waveguides. We show that if the array sufficiently samples the signal beam, a high-quality conjugate will be generated when the pump beams are counterpropagating. The ability of a waveguide mode to couple to incoming beams over a range of incident directions relaxes the strict phase-matching requirement present in bulkmedia four-wave mixing. A shift in the propagation direction of one of the pump beams changes the propagation direction of the generated beam while maintaining the spatial phase coherence.