High Performance Interband Cascade Lasers With AlGaAsSb Cladding Layers

Abstract

We report interband cascade lasers (ICLs) at 3.4 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> wavelength using bulk AlGaAsSb as the cladding layers for optical confinement, with device performance parameters at the same level as the best 5-stage ICLs using InAs/AlSb superlattice cladding layers. The threshold current density of broad area ICL with AlGaAsSb cladding layers has been reduced from the previously reported 220 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at room temperature to 130 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at 20 °C. Up to 80 °C operation in continuous-wave mode has been obtained for a 7- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> -wide narrow ridge waveguide ICL which has threshold current density of 177 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at 20 °C, and output power of 42 mW/facet from uncoated facet at 200 mA.