Prof. Ph.D.


2000 – 2005     Graduate Research Assistant, California Institute of Technology, Pasadena, CA, USA, Prof. A. Scherer
2002 – 2003 Integrated Photonics Designer, Luxtera Inc., Pasadena, CA, USA
2005 – 2005 Postdoctoral Scholar, California Institute of Technology, Prof. Axel Scherer
2006 – 2009 Sr. Engineer, Staff Engineer and Sr. Staff Engineer (Team Lead), Luxtera Inc., Carlsbad, CA, USA
2009 – 2010 Principal Research Scientist, University of Washington, Seattle, WA, USA
2011 – 2015 Professor (W2), Integrated Photonics Laboratory, RWTH Aachen University
2015 – present                     Professor (W3), Chair of Integrated Photonics, RWTH Aachen University


Academic Qualification and Education

2000       Diploma in Engineering, Ecole Polytechnique, Palaiseau, France
2001 M.Sc. Electrical Engineering, California Institute of Technology, Pasadena, CA, USA
2005 Ph.D. in Electrical Engineering, California Institute of Technology
2011 Professor at RWTH Aachen University


Teaching Experience

  • Optical Communications I: Devices (Winter Semesters, since 2012), M.Sc. Level
  • Optical Communications II: Systems (Summer Semesters, since 2012), M.Sc. Level
  • Electrical and Optical Measurement Systems (Winter Semesters, since 2014), M.Sc. Level
  • Laboratory Class for Third Semester Students (Summer Semesters, since 2013), B.Sc. Level

Honors, Awards, Scholarships and Other Appointments (Selection)

  • Senior Member of the IEEE (since 2016)
  • Starting Independent Researcher Award of the European Research Council (ERC, 2011)
  • Marie-Curie Career Reintegration Award (FP7, 2011)
  • Member of Board of Directors of „Center for Digital Photonic Production“ (91b research center)
  • Member of the European Alliance of Silicon Photonics ePIXfab (since 2016)
  • Coordinator of the FP7 EU-Project “Broadband Integrated and Green
  • Photonics Interconnects for High Performance Computing and Enterprise Systems” (BIG PIPES, 2013-2017)
  • General Chair of the “10th Sino-German Joint Symposium on Opto- and Microelectronic Devices and Systems” (Aachen, Germany, Sept. 2018 – Upcoming)
  • General Chair of the 2017 IEEE Conference on Group IV Photonics (Berlin, Germany)
  • Co-chair of the technical program subcommittee “Silicon Photonics Applications and Systems” of the IEEE Conference on Group IV Photonics 2016 (Shanghai, China)
  • Technical Program Chair of the “9th Sino-German Joint Symposium on Opto- and Microelectronic Devices and Systems” (Changchun, China, 2016)
  • Co-Chair of the Workshop “Next Generation Ultra-Broadband Silicon Photonics Based Integrated Circuits” at the 2016 European Conference on Optical Communications, Düsseldorf, Germany
  • Member of the Editorial Board of Scientific Reports (Nature Publishing Group, since 2015)


Research Topics

Silicon based integrated photonics with application to high-speed communications and sensing in the life sciences (biophotonics) at visible and infrared wavelengths.


Key Publications

  1. D. Stange, S. Wirths, R. Geiger, C. Schulte-Braucks, B. Marzban, N. von den Driesch, G. Mussler, T. Zabel, T. Stoica, J.-M. Hartmann, S. Mantl, Z. Ikonic, D. Grützmacher, H. Sigg, J. Witzens, D. Buca, “Optically Pumped GeSn Microdisk Lasers on Si,” ACS Photonics 3, 1279-1285 (2016).
  2. S. Sharif Azadeh, F. Merget, M. P. Nezhad, J. Witzens, “On the measurement of the Pockels effect in strained silicon,” Opt. Lett. 40(8), 1877-1880 (2015).
  3. J. Müller, F. Merget, S. Sharif Azadeh, J. Hauck, S. Romero García, B. Shen, J. Witzens, “Optical Peaking Enhancement in High-Speed Ring Modulators,” Sci. Rep. 4, Art. 6310 (2014).
  4. S. Romero-García, B. Marzban, F. Merget, B. Shen, J. Witzens, “Edge Couplers with relaxed Alignment Tolerance for Pick-and-Place Hybrid Integration of III-V Lasers with SOI Waveguides,” J. Sel. Top. Quant. Electron. 20(4), Art. 8200611 (2014).
  5. S. Romero-García, F. Merget, F. Zhong, H. Finkelstein, J. Witzens, “Silicon nitride CMOS-compatible platform for integrated photonics applications at visible wavelengths,” Opt. Express 21, 14037-14046 (2013).
  6. J. Witzens, T. Baehr-Jones, M. Hochberg, “Design of transmission line driven slot waveguide Mach-Zehnder interferometers and application to analog optical links,” Opt. Express 18, 16902-16928 (2010).
  7. G. Masini, G. Capellini, J. Witzens, Cary Gunn, “A Four-Channel, 10 Gbs Monolithic Optical Receiver in 130 nm CMOS with Integrated Ge Waveguide Photodetectors,” OFC post deadline paper PDP31 (2007).
  8. B. Maune, M. Loncar, J. Witzens, M. Hochberg, T. Baehr-Jones, D. Psaltis, Y. Qiu, A. Scherer, “Liquid-crystal electric tuning of a photonic crystal laser,” Appl. Phys. Lett. 85, 360-362 (2004).
  9. J. Witzens, M. Hochberg, T. Baehr-Jones, A. Scherer, “Mode matching interface for efficient coupling of light into planar photonic crystals,” Phys. Rev. E 69, Art. 046609 (2004).
  10. J. Witzens, M. Loncar, A. Scherer, “Self-Collimation in Planar Photonic Crystals,” IEEE J. Sel. Top. Quant. Electron. 8, 1246-1257 (2002).