Özgür Alaydin


Last Name

Alaydin

First Name

Özgür

ORCID

0000-0003-0935-4836

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2020 - 202221
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Publications 1 - 10 of 21
  • Towards 2-µm high-power ultrafast thin-disk laser
    Item type: Other Conference Item
    Wang, Y.; Tomilov, Sergei; Hoffmann, M.; et al. (2022)
  • Two Gigahertz Femtosecond Cr:ZnS Oscillator at 2.4 µm with 0.8-W Average Output Power
    Item type: Other Conference Item
    Barh, Ajanta; Alaydin, Özgür; Heidrich, Jonas; et al. (2021)
    OSA Technical Digest ~ Conference on Lasers and Electro-Optics
    We present a SESAM mode-locked self-starting Cr:ZnS oscillator delivering ~ 255 fs transform limited pulses at record high repetition rate above 2 GHz with average output power of 0.8 W at 2.4 µm.
  • Towards 2-µm high-power ultrafast thin-disk lasers
    Item type: Other Conference Item
    Wang, Yicheng; Yomilov, Sergei; Hoffmann, Martin; et al. (2021)
  • High average output power from a backside-cooled 2-µm InGaSb VECSEL with full gain characterization
    Item type: Other Conference Item
    Gaulke, Marco; Heidrich, Jonas; Alaydin, Özgür; et al. (2022)
    Proceedings of SPIE ~ Vertical External Cavity Surface Emitting Lasers (VECSELs) XI
    We report record performance and full gain characterization of an optically pumped continuous wave InGaSb VECSEL operating around 2 µm. Our flip-chip processed and backside-cooled VECSEL performs similar to intracavity heatspreader cooling and obtained even similar thermal resistance of only 3.45 KW-1 and an average output power of >800 mW. Our gain characterization setups can cover a wavelength range from 1.9 µm to 3 µm. Linear and nonlinear gain characteristics are measured as a function of wavelength, fluence, pump power and heatsink temperature. 2-µm VECSEL chips with different strategies in heat management are compared and theoretical predictions are in good agreement.
  • High-power low-noise 2-GHz femtosecond laser oscillator at 2.4 µm
    Item type: Journal Article
    Barh, Ajanta; Alaydin, Özgür; Heidrich, Jonas; et al. (2022)
    Optics Express
    Femtosecond lasers with high repetition rates are attractive for spectroscopic applications with high sampling rates, high power per comb line, and resolvable lines. However, at long wavelengths beyond 2 µm, current laser sources are either limited to low output power or repetition rates below 1 GHz. Here we present an ultrafast laser oscillator operating with high output power at multi-GHz repetition rate. The laser produces transform-limited 155-fs pulses at a repetition rate of 2 GHz, and an average power of 0.8 W, reaching up to 0.7 mW per comb line at the center wavelength of 2.38 µm. We have achieved this milestone via a Cr2+-doped ZnS solid-state laser modelocked with an InGaSb/GaSb SESAM. The laser is stable over several hours of operation. The integrated relative intensity noise is 0.15% rms for [10 Hz, 100 MHz], and the laser becomes shot noise limited (-160 dBc/Hz) at frequencies above 10 MHz. Our timing jitter measurements reveal contributions from pump laser noise and relaxation oscillations, with a timing jitter of 100 fs integrated over [3 kHz, 100 MHz]. These results open up a path towards fast and sensitive spectroscopy directly above 2 µm.
  • Bandgap engineering, monolithic growth, and operation parameters of GaSb-based SESAMs in the 2–2.4 µm range
    Item type: Journal Article
    Alaydin, Özgür; Gaulke, Marco; Heidrich, Jonas; et al. (2022)
    Optical Materials Express
    We present the detailed growth and characterization of novel GaSb-based semiconductor saturable absorber mirrors (SESAMs) operating in the 2–2.4 µm spectral range. These SESAMs at different wavelengths are bandgap engineered using ternary material compositions and without strain compensation. We observe that even when the thickness of quantum wells (QWs) exceeds the critical thickness we obtain strain relaxed SESAMs that do not substantially increase nonsaturable losses. SESAMs have been fabricated using molecular beam epitaxy with a AlAs0.08Sb0.92/GaSb distributed Bragg reflector (DBR) and strained type-I InxGa1−xSb or type-II W-like AlSb/InAs/GaSb QWs in the absorber region. All the type-I SESAMs show excellent performance, which is suitable for modelocking of diode-pumped semiconductor, ion-doped solid-state, and thin-disk lasers. The recovery time of the type-II SESAM is too long which can be interesting for laser applications. The dependence of the SESAM design, based on its QW number, barrier material, and operation wavelength are investigated. A detailed characterization is conducted to draw conclusions from macroscopic nonlinear and transient absorption properties at different wavelengths in the 2–2.4 µm range for the corresponding devices.
  • Power scaling of ultrafast 2-µm thin-disk laser oscillators
    Item type: Other Conference Item
    Tomilov, Sergei; Saraceno, Martin; Heidrich, Jonas; et al. (2022)
    Proceedings of SPIE ~ Solid State Lasers XXXI: Technology and Devices
    Many scientific and industrial applications can potentially benefit from high repetition rate, ultrafast short-wave infrared (SWIR) lasers operating at high average power. Modelocked thin-disk lasers are particularly promising in this aspect, as they can outperform amplifier schemes from a simple multi-MHz oscillator. In our work, we demonstrate latest advances in high-power 2µm TDLs, and present a continuous-wave Ho:YAG thin-disk oscillator with a record output power of 112 W, as well as SESAM modelocking of this source with up to 40.5 W of average power.
  • Full Mid-Infrared Characterization of InGaSb SESAMs
    Item type: Other Conference Item
    Heidrich, Jonas; Gaulke, Marco; Alaydin, Özgür; et al. (2021)
    OSA Technical Digest ~ Conference on Lasers and Electro-Optics
    We present high-precision (<0.04%) nonlinear reflectivity and pump-probe setups to characterize mid-infrared InGaSb quantum-well-based SESAMs at 2.05 µm. The SESAMs show modulation depths between 1-2.2%, low saturation fluences, low non-saturable losses and fast recovery times.
  • InGaSb SESAM modelocked high-power femtosecond Cr:ZnS oscillator at 2.4 µm with flexible repetition rates
    Item type: Other Conference Item
    Barh, Ajanta; Heidrich, Jonas; Alaydin, Özgür; et al. (2022)
    Proceedings of SPIE ~ Solid State Lasers XXXI: Technology and Devices
  • 2.4-µm SESAM modelocked high-power repetition rate scalable femtosecond Cr:ZnS oscillator
    Item type: Other Conference Item
    Barh, Ajanta; Alaydin, Özgür; Heidrich, Jonas; et al. (2021)
Publications 1 - 10 of 21