1. Reverse-Taper Mid-Infrared Quantum Cascade Lasers for Coherent Power Scaling.
- Author
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Ryu, Jae Ha, Knipfer, Benjamin, Kirch, Jeremy D., Marsland, Robert A., Botez, Dan, Earles, Tom, Galstad, Chris, Turville-Heitz, Morgan, Sigler, Chris, Stromberg, Axel, Sun, Yan-Ting, Lourdudoss, Sebastian, and Mawst, Luke J.
- Abstract
We present a reverse-taper quantum cascade laser (QCL) emitting at 4.6 μm, a novel-geometry device that can scale the output power while maintaining good beam quality. Buried-ridge waveguides with tapered and straight regions were formed by ICP etching and HVPE regrowth – the tapered region scales the output power, while the emitting facet is located at the narrow-end taper section, which provides mode filtering by suppressing high-order spatial modes. Beam profiles were observed under quasi-continuous-wave (QCW)/CW operation and beam quality (M2) measurements along with beam-stability measurements were performed – a small degree of collimated-beam centroid movement (<0.46 mrad, peak-to-peak) was observed, along with M2 values close to 1 up to ∼1 W QCW power. Devices of shorter cavity lengths were also investigated, indicating that the output power scales with the core-region volume but results in a small increase in angular deviation. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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