7.3 Mid-IR to Near-IR conversion

The mid-infrared (mid-IR) spectral region has attracted a significant amount of interest in recent years. It contains the absorption "fingerprints" of most molecules of interest, thus suggesting several applications both in spectroscopy and chemical and biomolecular sensing. The recent development of mid-IR sources, most notably quantum cascade lasers (QCLs), has further stimulated the interest of the research community in this area. However, the lack of small size, room temperature detectors exhibiting suitably high sensitivity at this wavelength region still remains an issue.

 

To overcome this difficulty, wavelength conversion of the mid-IR signals into the near-infrared (near-IR) is a promising alternative. Silicon is an excellent candidate for such applications, thanks to its transparency up to 8 µm, the reduced two-photon and free-carrier absorptions beyond 2 µm and its potential for monolithic integrated solutions. These features however, are not restricted to pure silicon. For instance, silicon germanium (SiGe) alloys have been identified as promising candidates for nonlinear applications in the midwave and longwave infrared thanks to their enhanced nonlinearity compared to pure Si.

Since 2011, our group in collaboration with other leading institutes and universities in Europe has strong activity in the design, fabrication and characterization of SiGe waveguides tailored for the conversion of mid-infrared signals to the near-infrared based on four-wave mixing (CLARITY EU project). The broadest conversion we have demonstrated up to date is from 2.65 µm to 1.77 µm using a pump at 2.12 µm.

 

Related projects:

  • CLARITY
  • COST MP1204 (“TERA-MIR Radiation:  Materials, Generation, Detection and Applications”) 

 

Significant publications: 

  • Kamal Hammani, Mohamed A. Ettabib, Adonis Bogris, Alexandros Kapsalis, Dimitris Syvridis, Mickael Brun, Pierre Labeye, Sergio Nicoletti, and Periklis Petropoulos, “Towards nonlinear conversion from mid- to near-infrared wavelengths using Silicon Germanium waveguides,” Optics Express, Vol. 22, Issue 8, pp. 9667-9674 (2014).
  • Kamal Hammani, Mohamed A. Ettabib, Adonis Bogris, Alexandros Kapsalis, Dimitris Syvridis, Mickael Brun, Pierre Labeye, Sergio Nicoletti, David J. Richardson, and Periklis Petropoulos, “Optical properties of silicon germanium waveguides at telecommunication wavelengths,” Optics Express, Vol. 21, Issue 14, pp. 16690-16701 (2013).
  • Mohamed A. Ettabib, Kamal Hammani, Francesca Parmigiani, Liam Jones, Alexandros Kapsalis, Adonis Bogris, Dimitris Syvridis, Mickael Brun, Pierre Labeye, Sergio Nicoletti, and Periklis Petropoulos, “FWM-based wavelength conversion of 40 Gbaud PSK signals in a silicon germanium waveguide,” Optics Express, Vol. 21, Issue 14, pp. 16683-16689 (2013).