Abstract

Numerical calculations of the free-running modes of a ten-stripe gain-guided diode laser array predict the existence of modes of order >10, which represents a sharp contrast to coupled-mode theory. In this paper we show that the inclusion of junction heating in our model results in a real refractive-index profile across the width of the array. This index variation results in a strong field confinement within the device, which alters the spatial distributions and relative gains of the array eigenmodes. Our calculations show that a 10° rise in the temperature of the active region (resulting in an index increase of >0.01) produces appreciable changes in the near-field intensity profiles and observable increases in the far-field emission angles for the higher-order (v ≥ 10) modes. Junction heating also decreases the spread in gain of the high-order array modes (v ≥ 10) and accounts for their observation in high-power gain-guided arrays. The inclusion of junction heating in our model will be shown to markedly improve the agreement between our numerical predictions and laboratory observations on the eigenmodes of gain-guided diode laser arrays.

© 1986 Optical Society of America