Analysis of the Cross-Coupled Lateral Mode in a Twin-Stripe Four-Contact Laser with Diagonal Current Injection

Cross-coupled resonant lateral modes in a twin-stripe four-contact laser are analyzed by coupled-mode theory for conditions in which the current injection into each diagonal pair of stripes is equal. Dependence of the optical power distribution on the laser length, and on the carrier-density or the current-density distribution are investigated. The most interesting result is that the highest optical power appears in the waveguide with the lowest carrier density when the carrier-density difference between the adjacent waveguides is small and the laser is shorter than the coupling length. This allows us to show that a cross-coupled mode can be supported even in a two-contact twin-stripe laser, and a bistable switching between the mode and its mirror image is possible.