Vertically Coupled Partially Tapered Ridge Waveguide Semiconductor FP Laser With Improved Divergence Angles

In this work, we present a semiconductor FP laser design with significantly reduced divergence angles particularly in the vertical direction. The laser has a pair of vertically stacked, propagation constant unmatched twin waveguides that is coupled by a tapered ridge at the output end. As such, the laser has a significantly extended mode profile at the output section while the light propagation in the main section is not affected. Our …