LATERAL SPATIAL EFFECTS OF FEEDBACK IN GAIN-GUIDED AND BROAD-AREA SEMICONDUCTOR-LASERS

Starting from Fresnel diffraction theory, we derive analytic expressio ns for the lateral spatial dependence of feedback fields for the cases of conventional and phase-conjugate optical feedback, By using numeri cal simulations we show that for narrow-stripe gain-guided lasers, bot h types of optical feedback from an external cavity fan convert the tw in-lobed far fields into a nearly single-lobed far held, We also find that conventional and phase-conjugate feedbacks in broad-area lasers i nduce a spatial modulation of the lateral held that increases the tend ency for filamentation at moderate (-30 dB) feedback levels.