{"ID":2893145,"CreatedAt":"2026-06-01T04:54:23.091178241Z","UpdatedAt":"2026-06-01T04:54:23.091178241Z","DeletedAt":null,"paper_url":"https://arxiv.org/abs/2507.14003","arxiv_id":"2507.14003","title":"Hybrid Integration of Quantum Cascade Lasers with Germanium-on-Silicon waveguides for Mid-Infrared Sensing Applications","abstract":"We present a novel scheme for hybrid integration of quantum cascade laser bars with germanium-on-silicon waveguides operating in the mid-infrared. The laser bars are flip-chip bonded onto a germanium-on-silicon target chip without active alignment, acheiving end-fire coupling efficiency of up to 45% (3.5 dB loss) in pulsed operation. Optical power estimates indicate 20-30 mW coupled into the waveguides. The passive alignment approach, combined with a CMOS-compatible photonic integrated circuit fabrication process, offers a scalable pathway to fully integrated mid-infrared photonic systems for sensing, free-space communications, and the realisation of novel light sources.","short_abstract":"We present a novel scheme for hybrid integration of quantum cascade laser bars with germanium-on-silicon waveguides operating in the mid-infrared. The laser bars are flip-chip bonded onto a germanium-on-silicon target chip without active alignment, acheiving end-fire coupling efficiency of up to 45% (3.5 dB loss) in pu...","url_abs":"https://arxiv.org/abs/2507.14003","url_pdf":"https://arxiv.org/pdf/2507.14003v1","authors":"[\"Colin J. Mitchell\",\"Longqi Zhou\",\"Ke Li\",\"Daniel Adeyemi\",\"Ahmed Osman\",\"Milos Nedeljkovic\",\"Glenn Churchill\",\"James C. Gates\",\"Graham T. Reed\",\"Kristian M. Groom\",\"Jon Heffernan\",\"Goran Mashanovich\"]","published":"2025-07-18T15:16:57Z","proceeding":"physics.optics","tasks":"[\"physics.optics\",\"eess.SP\",\"physics.app-ph\"]","methods":"[]","has_code":false}