Semiconductor quantum dot lasers for generation of optical frequency combs

Optical frequency combs can be generated in edge-emitting semiconductor lasers exploiting passive or active mode-locking techniques that have been demonstrated more than 30 years ago. In the last ten years, it has been shown that laser diodes based on quantum dot active region can generate very wide and stable combs not only in passive mode-locking regimes (ie: two section laser with gain and saturable absorber) but also in self- mode locking regimes relying only on the gain session.

We have developed a Time Domain Traveling Wave numerical simulator that accounts for the peculiar characteristics of the quantum dot active material (inhomogeneous gain broadening, carrier dynamics in quantum dot confined states, double state emission from both ground state and excited state, spatial hole burning …) to simulate passive, active and self-mode locking in QD lasers.

The tool is now applied at:

  • design of QD lasers at 980 nm for the generation of ultra-short pulses at low (a few GHz) repetition rates for pumping single photon sources
  • study self-generation of optical frequency combs in QD lasers directly grown on silicon

The tool has already assisted some international research labs and companies in the design of their lasers and/or the interpretation of experimental results obtained.

Erc Sector:

  • PE7_3 Simulation engineering and modelling
  • PE7_5 (Micro and nano) electronic, optoelectronic and photonic components
  • PE7_6 Communication technology, high-frequency technology


  • Laser modelocking
  • Quantum dot laser
  • Optical frequency combs
  • Self-mode locking