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Author: Knigge, Andrea × End date: 2023 × Start date: 2023 × End date: 2024 × Start date: 2020 × Has files: Yes × Type: Article × Type: Text ×

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Now showing 1 - 3 of 3
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    Wavelength-stabilized ns-pulsed 2.2 kW diode laser bar with multiple active regions and tunnel junctions
    (Stevenage : IET, 2022) Ammouri, Nor; Christopher, Heike; Fricke, Jörg; Ginolas, Arnim; Liero, Armin; Maaßdorf, Andre; Wenzel, Hans; Knigge, Andrea
    The improvement of the performance of a distributed Bragg reflector laser bar emitting near 905 nm through the use of multiple epitaxially stacked active regions and tunnel junctions is reported. The bar consisting of 48 emitters (each having an aperture of 50 µm) emits an optical power of 2.2 kW in 8 ns long pulses at an injection current of 1.1 kA. This corresponds to an almost threefold increase of the pulse power compared to a bar with lasers having only a single active region. Due to the integrated surface Bragg grating, the bar exhibits a narrow spectral bandwidth of about 0.3 nm and a thermal tuning of only 68 pm/K.
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    Simulation and analysis of high-brightness tapered ridge-waveguide lasers
    (Dordrecht [u.a.] : Springer Science + Business Media B.V, 2023) Koester, Jan-Philipp; Wenzel, Hans; Wilkens, Martin; Knigge, Andrea
    In this work, a simulation-based analysis of a CW-driven tapered ridge-waveguide laser design is presented. Measurements of these devices delivered high lateral brightness values of 4 W · mm - 1mrad - 1 at 2.5W optical output power. First, active laser simulations are performed to reproduce these results. Next, the resulting complex valued intra-cavity refractive index distributions are the basis for a modal and beam propagation analysis, which demonstrates the working principle and limitation of the underlying lateral mode filter effect. Finally, the gained understanding is the foundation for further design improvements leading to lateral brightness values of up to 10 W · mm - 1mrad - 1 predicted by simulations.
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    Hybrid integrated mode-locked laser using a GaAs-based 1064 nm gain chip and a SiN external cavity
    (Washington, DC : Soc., 2022) Vissers, Ewoud; Poelman, Stijn; Wenzel, Hans; Christopher, Heike; Van Gasse, Kasper; Knigge, Andrea; Kuyken, Bart
    External cavity mode-locked lasers could be used as comb sources for high volume application such as LIDAR and dual comb spectroscopy. Currently demonstrated chip scale integrated mode-locked lasers all operate in the C-band. In this paper, a hybrid-integrated external cavity mode-locked laser working at 1064 nm is demonstrated, a wavelength beneficial for optical coherence tomography or Raman spectroscopy applications. Additionally, optical injection locking is demonstrated, showing an improvement in the optical linewidth, and an increased stability of the comb spectrum.