AlInGaAs/InP 1.55-<i>μ</i>m High-Index-Contrast Circular Beam Edge-Emitting Semiconductor Lasers

We experimentally demonstrate deep-etched 1550 nm AlInGaAs/InP single spatial mode high-index-contrast ridge waveguide (HIC RWG) edge-emitter semiconductor diode lasers operating with a non-astigmatic circular output beam, achieving a total output power of 23 mW cw and 31 mW pulsed for unbonded die. By selectively wet etching the AlInGaAs graded-index separate confinement heterostructure (GRINSCH) laterally inward from the sidewalls of a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.75~\mu $ </tex-math></inline-formula>m dry-etched ridge, the remaining <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.67~\mu $ </tex-math></inline-formula>m active core yields a circular <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.6~\mu $ </tex-math></inline-formula>m <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1/e^{2}$ </tex-math></inline-formula> width TEM00 Gaussian near field mode with ~30° FWHM far field divergence angle for both X and Y axes.