Highly efficient channel waveguide lasers at 1 µm and 2 µm in refractive-index-engineered potassium double tungstates

Koop van Dalfsen, Dimitri Geskus, Sonia M. García-Blanco, Markus Pollnau

    Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademic

    Abstract

    Epitaxial growth of rare-earth-ion-activated KY(1-x-y)Gd(x)Lu(y)(WO4)2 co-doped thin layers onto KY(WO4)2 substrates has enabled lattice-matched waveguides with high refractive-index contract and large variation of the active rare-earth-ion concentration. In Yb3+-activated micro-structured channel waveguides, we demonstrated lasers with 418 mW of continuous-wave output power at 1023 nm and a slope efficiency of 71% versus launched pump power at 981 nm. Channel waveguide lasers operating on the 981-nm zero-phonon line were demonstrated under pumping at 934 nm with an output power of 650 mW and a slope efficiency of 76% versus absorbed pump power. Lasing with a record-low quantum defect of 0.7% was achieved. In a feasibility study, a device comprising a tapered active channel waveguide and a passive planar pump waveguide, fabricated by multi-layer growth of lattice-matched layers, was demonstrated as a laser by diode-side pumping with a high-power, multi-mode diode bar. This approach offers the potential for significantly increased output powers from channel waveguide lasers. Tm3+-activated channel waveguide lasers demonstrated a maximum output power of 300 mW and slope efficiency of 70%, when pumping near 800 nm. Lasing was obtained at various wavelengths between 1810 nm and 2037 nm. These lasers were operated with resonators exploiting either butt-coupled mirrors, providing only a non-permanent solution, or based on Fresnel reflection at the waveguide end-facets, resulting in laser emission from both waveguide ends and without control of the laser wavelength. Currently we are inscribing Bragg gratings into the top cladding to provide a stable resonator configuration that allows for effective wavelength selection.
    Original languageEnglish
    Title of host publicationSolid State Lasers XXII
    Subtitle of host publicationTechnology and Devices
    Place of PublicationBellingham, WA
    PublisherSPIE
    Number of pages1
    Publication statusPublished - Feb 2013
    EventSPIE Laser Source Technologies and Industrial Lasers and Applications Conference, LASE 2013 - The Moscone Center, San Francisco, United States
    Duration: 2 Feb 20137 Feb 2013

    Conference

    ConferenceSPIE Laser Source Technologies and Industrial Lasers and Applications Conference, LASE 2013
    Abbreviated titleLASE
    CountryUnited States
    CitySan Francisco
    Period2/02/137/02/13

    Keywords

    • IOMS-APD: Active Photonic Devices
    • IR-84573
    • METIS-296345
    • EWI-23151

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  • Cite this

    van Dalfsen, K., Geskus, D., García-Blanco, S. M., & Pollnau, M. (2013). Highly efficient channel waveguide lasers at 1 µm and 2 µm in refractive-index-engineered potassium double tungstates. In Solid State Lasers XXII: Technology and Devices [8599-2] Bellingham, WA: SPIE.