Quantum Photonics & Optoelectronics

Quantum Photonics:

The development of scalable quantum photonic integrated circuits (QPICs) is essential for the future of quantum communication, sensing, and computing. However, realizing on-chip quantum light sources and single-photon detectors in a silicon-based platform remains a fundamental challenge. Our research tackles this issue by integrating color centers in silicon as telecom-wavelength quantum emitters and leveraging chalcogen-implanted silicon avalanche photodiodes (APDs) for efficient single-photon detection.

By using ion implantation, annealing, and advanced lithographic techniques, we engineer and position these quantum defects within photonic structures, enabling their seamless integration with waveguides and resonators. This approach ensures compatibility with existing silicon photonics technology, paving the way for scalable, CMOS-compatible quantum architectures that can be deployed in large-scale optical networks.

Optoelectronics:

Our research focuses on harnessing group-IV semiconductors, such as silicon (Si) and germanium (Ge), to enable next-generation photonic technologies compatible with standard CMOS fabrication. By engineering Ge through Sn alloying, high-level n-type doping, and strain techniques, we transform it into a direct-bandgap material with emission in the short-wavelength infrared range.

In parallel, we enhance silicon’s infrared detection capabilities by introducing chalcogens at concentrations near their solid solubility limit. Using ion implantation followed by thermal treatments, we extend Si’s photoresponse to energies below its band gap, unlocking new possibilities for on-chip photonic integration and optical sensing.

Additionally, we explore plasmonic effects in group-IV semiconductors, leveraging highly doped Si and Ge to support tunable localized surface plasmons in the infrared range. This approach enables subwavelength light confinement and enhanced light-matter interaction, opening new avenues for integrated photonics and optoelectronic devices.

These advancements pave the way for high-performance, energy-efficient photonic devices seamlessly integrated with silicon microelectronics.

Third-party projects:

  • Innovation Fund Denmark: Erbium-based silicon quantum light sources (EQUAL), start 05/25
  • HHIF: Dual-band silicon optical sensor (D-BAND), start 02/25
  • BMBF: On-chip realization and integration of electrically driven silicon single photon sources in the optical telecommunication band (ORION), start 01/25
  • SAB: Cost-effective CMOS-based GeSn shortwave infrared photodetectors (GeSn-SWIR), start 12/24
  • DFG: Ultradoped GeSn-based plasmonic antennas and GeSn/Si plasmon-enhanced heterojunction photoemission infrared photodetectors on the Si platform, start 02/24

Team:

- PI: Yonder Berencén

- Postdoc: Shuyu (Greg) Wen

- Postdoc: Saif Mohd Shaikh

- Postdoc: Yi Li

- Ph.D. student: Peiting Wen

- Ph.D. student: Guillermo Godoy-Pérez

- Ph.D. student: Alessandro Puddu

- Ph.D. student: Junchun Yang

Collaborators:

- Prof. Kambiz Jamshidi (Technische Universität Dresden — TUD)

- Prof. Tim Schröder (Humboldt-Universität zu Berlin)

- Prof. Inga A. Fischer (Brandenburg University of Technology Cottbus-Senftenberg — BTU)

- Prof. Søren Stobbe (Technical University of Denmark — DTU)

- Prof. Ing-Song Yu (National Dong Hwa University / Taiwan)

Selected publications:

[1] Shaikh, M. S., et. al. A high-performance all-silicon photodetector enabling telecom-wavelength detection at room temperature, Under Review (2025). https://www.researchsquare.com/article/rs-5623025/v1

[2] Wen, S., et al, Optical spin readout of a silicon color center in the telecom L-band, Under Review (2025). https://doi.org/10.48550/arXiv.2502.07632

[3] Wen, S., et al, Room-temperature extended short-wave infrared GeSn photodetectors realized by ion beam techniques, Appl. Phys. Lett. 123, 081109 (2023)

[4] Hollenbach, M., et. al. Wafer-scale nanofabrication of telecom single-photon emitters in silicon. Nat Commun 13, 7683 (2022).

[5] Hollenbach, M., et. al. Engineering telecom single-photon emitters in silicon for scalable quantum photonics. Opt. Express 28, 26111-26121 (2020).