Multi-wavelength semiconductor lasers

Title of the research project

Development of simulation tools for the analysis and design of single section comb semiconductor lasers based on nanostructured materials

 Scientific area 

Photonics; Active components for optical communications; semiconductor lasers;

Project coordinator

Mariangela Gioannini

Abstract 

The project has studied the physics and the methods for the design of multi-wavelength semiconductor lasers (comb lasers) realized with one single active section and nano-structured materials. We have considered both laser diodes at optical communication wavelengths and quantum cascade lasers with emission in the Mid_IR or THz region.

Description of the research project 

The project idea was inspired by the several experimental results obtained in various international research labs, who have shown that single section semiconductor lasers with quantum dot or quantum cascade active region can generate a broad optical spectrum of several emission lines with same amplitude and perfectly equally spaced. These lasers are defined comb lasers. Despite the many experimental results, it is still not clear  the physical origin of this multi-wavelength emission with phase locked modes. In this project we have investigated complex physical models accounting for the peculiar characteristics of the nano-structured materials. Based on these models, we have developed simulation tools to study and design comb lasers. Through the comparison between experimental and simulation results, we have clarified the physical origin of the phase locking and have supported the experimental partners in the understanding of their experimental results.

Since the laser emission lines can be considered equivalent to a network of coupled oscillators, the project team has included also the expertise of the DET group active in the study of linear and non-linear circuits. The group has investigated the similarities between the comb lasers and other networks of coupled oscillators providing advancements in the understanding of the synchronisation mechanism in laser combs.

Impact on society 

The understanding of the physical principles behind the comb generation in single section lasers will improve their design and favour their use in the industry as laser sources for high bit rate (multi Tbit/s) optical interconnect in data centres. Comb lasers, generating a multi-wavelength spectrum, can indeed substitute complicate laser arrays that are difficult to integrate and control.

Research Results

The theoretical model and the comb laser simulator developed by the project enhanced the comprehension of the physical characteristics of this laser, so allowing to significantly increase the signal-noise ratio in the transmission channels thus improving the quality of transmission. The project has also started a young team of researchers skilled in the numerical simulation and design of photonic devices.

In particular:

  • Invited presentations to international conferences
  • New collaborations with top universities such as ETH Zurich, Université de Paris Diderot, Technical University Darmstadt
  • New collaborations with industrial research centers such as CISCO Systems
  • Realization of the first Silicon Photonics chip at Politecnico di Torino (supported by the Europractice consortium)

Working group 

At Politecnico di Torino

Mariangela Gioannini (project coordinator), Paolo Bardella, Michele Bonnin, Federica Cappelluti, Lorenzo Luigi Columbo , Javad Rahimi , Arastoo Khalili 

International Partners

Semiconductor Optics Group Technical University of Darmstadt, Germania

Laboratoire Matériaux et Phénomènes Quantiques of Univeristy Paris-Diderot, Francia

III-V Lab, Francia

  • Budget: 148.000
  • Start date: 15/12/2015
  • End date: 14/12/2017