Giacomo Scalari


Last Name

Scalari

First Name

Giacomo

ORCID

0000-0003-4028-803X

Organisational unit

03759 - Faist, Jérôme / Faist, Jérôme

Search Results

Publications 1 - 10 of 291
  • Bound-to-continuum terahertz quantum cascade laser with a single-quantum-well phonon extraction/injection stage
    Item type: Journal Article
    Amanti, Maria I.; Scalari, Giacomo; Terazzi, Romain; et al. (2009)
    New Journal of Physics
    A terahertz quantum cascade laser design that combines a wide gain bandwidth, large photon-driven transport and good high-temperature characteristics is presented. It relies on a diagonal transition between a bound state and doublet of states tunnel coupled to the upper state of a phonon extraction stage. The high optical efficiency of this design enables the observation of photon-driven transport over a wide current density range. The relative tolerance of the design to small variations in the barrier thicknesses made it suitable for testing different growth techniques and materials. In particular, we compared the performances of devices grown using molecular-beam epitaxy with those achieved using organometallic chemical vapor deposition. The low-threshold current density and the high slope efficiency makes this device an attractive active region for the development of single-mode quantum cascade lasers based on third-order-distributed feedback structures. Single-mode, high power was achieved with good continuous and pulsed wave operation.
  • Photon-Driven Broadband Emission and Frequency Comb RF Injection Locking in THz Quantum Cascade Lasers
    Item type: Journal Article
    Forrer, Andres; Franckié, Martin; Stark, David; et al. (2020)
    ACS Photonics
  • Spectroscopic determination of the doping and mobility of terahertz quantum cascade structures
    Item type: Journal Article
    Lloyd-Hughes, James; Delley, Yves Léandre; Scalari, Giacomo; et al. (2009)
    Journal of Applied Physics
    Terahertz time-domain spectroscopy is shown to provide a convenient and rapid means to measure the conductivity of individual layers in semiconductor heterostructures such as terahertz quantum cascade lasers. By modeling the complex transmission at terahertz frequencies, the electron density and the in-plane momentum scattering time of the active regions and doped contact layers were determined for both GaAs/AlGaAs and InGaAs/InAlAs epilayers. The measured temperature dependence of the electron scattering rate revealed the significance of impurity and LO phonon scattering. The implications for laser operation at room temperature are discussed by considering the changes in absorption and resonant tunneling current with temperature.
  • Terahertz absorption-saturation and emission from electron-doped germanium quantum wells
    Item type: Journal Article
    Ciano, Chiara; Virgilio, Michele; Bagolini, Luigi; et al. (2020)
    Optics Express
  • Staggered Phase Flux for Frequency Comb Shaping in Fast Gain Lasers
    Item type: Other Conference Item
    Piciocchi, Diego; Dikopoltsev, Alex; Heckelmann, Ina; et al. (2025)
    2025 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)
  • Coherent walk and lock in driven fast-gain frequency-combs
    Item type: Other Conference Item
    Heckelmann, Ina; Bertrand, Mathieu; Dikopoltsev, Alex; et al. (2023)
    EPJ Web of Conferences ~ EOS Annual Meeting (EOSAM 2023)
    Locking multiple modes into a frequency comb is key for multiple metrological applications, and a great effort has been therefore invested in this challenge over the last decade. The most common techniques are based on either nonlinearities or modulation of the cavity, while the latter is considered the more controllable method to produce frequency combs. The modulation couples cavity modes and creates a lattice in a synthetic dimension with coherent walk dynamics, but typically these dynamics are overthrown by the dissipative processes, leading to a spectrum that is narrow relatively to the full frequency ladder potential. Here we propose and demonstrate that by using fast-gain we preserve the full potential of the coherent walk and lock the frequency comb at its maximum possible bandwidth. Moreover, we find in our system a unique regime of dissipative fast-gain Bloch oscillations. We demonstrate these dynamics in RF-modulated quantum cascade laser ring devices.
  • Single Quantum Walk Comb Spectroscopy
    Item type: Other Conference Item
    Pinto, Davide; Heckelmann, Ina; Bertrand, Mathieu; et al. (2025)
  • Retrieving the Phase Relation of a Quantum Cascade Laser Frequency Comb and Reconstructing its Emission Profile
    Item type: Conference Paper
    Cappelli, Francesco; Consolino, Luigi; Campo, Giulio; et al. (2019)
    2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)
  • FM to AM Transition of RF Driven THz QCL fundamental and Harmonic Comb States
    Item type: Other Conference Item
    Forrer, Andres; Cibella, Sara; Senica, Urban; et al. (2022)
    2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)
    We measure temporal intensity profile by means of Shifted Wave Interference Fourier Transform Spectroscopy of strong RF injected heterogeneous THz QCLs showing a strong AM emission with pulses as short as 6 ps. Additionally, we measure with SWIFTS fundamental as well as harmonic comb states under RF injection which exhibit clear FM emission and its transition to AM as a function of the RF power.
  • High-Resolution Rotational Fourier-Transform Infrared Spectroscopy
    Item type: Other Conference Item
    Markmann, Sergej; Franckié, Martin; Bertrand, Mathieu; et al. (2022)
    2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)
    We demonstrate a rotational optical delay line for Fourier transform infrared (FTIR) spectroscopy with simultaneous high time and frequency resolutions. Thanks to the rotational motion, the trade-off between speed and spectral resolution present in rapid-scan FTIRs is alleviated, and enables the use of high-brightness quantum cascade laser frequency combs as light sources. We demonstrate the capabilities of the delay line by resolving low-pressure methane absorption lines and tracking several absorption lines at video frame rates.
Publications 1 - 10 of 291