High-speed integrated Silicon Germanium optical modulator with 3 GHz bandwidth in the 5-9 µm wavelength range
Mid-infrared spectroscopy is a powerful technique for identifying chemical and biological substances, increasing the demand for compact and cost-effective integrated systems. In this context, integrated electro-optic modulators are essential to implement advanced techniques such as synchronous detection or dual-comb spectroscopy. In this paper, we present a waveguide-integrated electro-optic modulator operating in a broad spectral range from 5 to 9 µm wavelength, based on a Schottky diode embedded in a graded silicon germanium waveguide. By using the free-carrier plasma absorption effect, the device achieves an extinction ratio of up to 1.9 dB at a wavelength of 9 µm. Two different methods have been used to evaluate the device speed. In both cases, high-speed operation up to 7 GHz is obtained, while the optical bandwidth is estimated to be around 3 GHz. These results represent a significant step forward in both the development of characterization techniques and in the performance of mid-IR integrated modulators, paving the way for high-performance on-chip spectroscopic systems.
Authors
- Delphine Marris‐Morini (ORCID: https://orcid.org/0000-0002-1324-5029)
- Stefano Calcaterra (ORCID: https://orcid.org/0009-0001-7543-8360)
- Victor Turpaud (ORCID: https://orcid.org/0009-0000-1643-4004)
- David Bouville (ORCID: https://orcid.org/0000-0002-2979-3599)
- Jean‐François Lampin (ORCID: https://orcid.org/0000-0001-8309-8178)
- Hamza Dely (ORCID: https://orcid.org/0000-0002-0457-5384)
- Afonso DE CERDEIRA OLIVEIRA
- Étienne Herth (ORCID: https://orcid.org/0000-0002-8321-5060)
- E. Peytavit (ORCID: https://orcid.org/0000-0002-0074-4339)
- S. Barbieri (ORCID: https://orcid.org/0000-0003-4024-8898)
- Jacopo Frigerio (ORCID: https://orcid.org/0000-0003-2117-2744)
- R. Colombelli (ORCID: https://orcid.org/0000-0002-1540-9920)
- Gia Long Ngo (ORCID: https://orcid.org/0000-0002-9640-0433)
- Jean‐René Coudevylle (ORCID: https://orcid.org/0009-0004-7299-1592)
- Thi Hao Nhi Nguyen (ORCID: https://orcid.org/0000-0003-4939-7961)
- Giovanni Isella (ORCID: https://orcid.org/0000-0001-5951-7440)
- Victor Merupo (ORCID: https://orcid.org/0000-0002-4947-8086)
- Adel Bousseksou (ORCID: https://orcid.org/0000-0001-8802-3239)
- Luca Lucia (ORCID: https://orcid.org/0009-0008-6923-627X)
- Samson Edmond
- Davide Impelluso
- Javier Huertas-Pedroche
Publication Details
- Journal
- Optics Express
- Published
- 2025-09-15
- DOI
- https://doi.org/10.1364/oe.572563
- Primary Topic
- Photonic and Optical Devices
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- European Commission
- HORIZON EUROPE Framework Programme
- HORIZON EUROPE European Innovation Council