Filters

2020 - 20223

More filters

2021 - 20223
Reset filters

Settings

End date: 2024 × DDC: 530 × Publisher: Washington, DC : Soc. × WGL Institute: IHP ×

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Si photonic-electronic monolithically integrated optical receiver with a built-in temperature-controlled wavelength filter
    (Washington, DC : Soc., 2021) Kim, Hyun-Kyu; Kim, Minkyu; Kim, Min-Hyeong; Jo, Youngkwan; Lischke, Stefan; Mai, Christian; Zimmermann, Lars; Choi, Woo-Young
    We present a Si photonic-electronic integrated ring-resonator based optical receiver that contains a temperature-controlled ring-resonator filter (RRF), a Ge photodetector, and receiver circuits in a single chip. The temperature controller automatically determines the RRF temperature at which the maximum transmission of the desired WDM signal is achieved and maintains this condition against any temperature or input wavelength fluctuation. This Si photonic-electronic integrated circuit is realized with 0.25-µm photonic BiCMOS technology, and its operation is successfully confirmed with measurement.
  • Thumbnail Image
    Item
    Design and simulation of losses in Ge/SiGe terahertz quantum cascade laser waveguides
    (Washington, DC : Soc., 2020) Gallacher, K.; Ortolani, M.; Rew, K.; Ciano, C.; Baldassarre, L.; Virgilio, M.; Scalari, G.; Faist, J.; Gaspare, L.D.I.; Seta, M.D.E.; Capellini, G.; Grange, T.; Birner, S.; Paul, D.J.
    The waveguide losses from a range of surface plasmon and double metal waveguides for Ge/Si1-xGex THz quantum cascade laser gain media are investigated at 4.79 THz (62.6 µm wavelength). Double metal waveguides demonstrate lower losses than surface plasmonic guiding with minimum losses for a 10 µm thick active gain region with silver metal of 21 cm-1 at 300 K reducing to 14.5 cm-1 at 10 K. Losses for silicon foundry compatible metals including Al and Cu are also provided for comparison and to provide a guide for gain requirements to enable lasers to be fabricated in commercial silicon foundries. To allow these losses to be calculated for a range of designs, the complex refractive index of a range of nominally undoped Si1-xGex with x = 0.7, 0.8 and 0.9 and doped Ge heterolayers were extracted from Fourier transform infrared spectroscopy measurements between 0.1 and 10 THz and from 300 K down to 10 K. The results demonstrate losses comparable to similar designs of GaAs/AlGaAs quantum cascade laser plasmon waveguides indicating that a gain threshold of 15.1 cm-1 and 23.8 cm-1 are required to produce a 4.79 THz Ge/SiGe THz laser at 10 K and 300 K, respectively, for 2 mm long double metal waveguide quantum cascade lasers with facet coatings. © 2020 OSA - The Optical Society. All rights reserved.
  • Thumbnail Image
    Item
    Quantitative protein sensing with germanium THz-antennas manufactured using CMOS processes
    (Washington, DC : Soc., 2022) Hardt, Elena; Chavarin, Carlos Alvarado; Gruessing, Soenke; Flesch, Julia; Skibitzki, Oliver; Spirito, Davide; Vita, Gian Marco; Simone, Giovanna De; Masi, Alessandra di; You, Changjiang; Witzigmann, Bernd; Piehler, Jacob; Capellini, Giovanni
    The development of a CMOS manufactured THz sensing platform could enable the integration of state-of-the-art sensing principles with the mixed signal electronics ecosystem in small footprint, low-cost devices. To this aim, in this work we demonstrate a label-free protein sensing platform using highly doped germanium plasmonic antennas realized on Si and SOI substrates and operating in the THz range of the electromagnetic spectrum. The antenna response to different concentrations of BSA shows in both cases a linear response with saturation above 20 mg/mL. Ge antennas on SOI substrates feature a two-fold sensitivity as compared to conventional Si substrates, reaching a value of 6 GHz/(mg/mL), which is four-fold what reported using metal-based metamaterials. We believe that this result could pave the way to a low-cost lab-on-a-chip biosensing platform.