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Free Upcoming WEBINAR series – PART II

Semiconductor lasers: Cavity enhanced high speed DMLs & Introduction to LaserMatrix Software

Wednesday, February 21, 2024

10.00-12.00 AM CET (including 15 min. break)

(Recording will be emailed post event to all registrants)

Speaker/Instructor: Richard Schatz, Senior researcher and lecturer, KTH Royal Institute of Technology, Stockholm


In this webinar I will give an introduction to semiconductor lasers for high speed optical communication. The directly modulated laser (DML) is a key component in optical datacom due to its simple fabrication, high modulation bandwidth and high output power. The modulation bandwidth of single section DMLs is limited by electrical parasitics, thermal effects and an overdamped response at high bias. In multi-section DMLs, the bandwidth can be enhanced by utilizing the wavelength selectivity of the laser cavity. Three effects will be discussed; detuned loading, photon-photon resonance and chirp to intensity conversion.

In the second part of the seminar, I will give an introduction to the LaserMatrix software, a user-friendly CAD-tool, developed for designing the longitudinal cavity of semiconductor lasers. Simulation examples will be presented and compared with the time domain model of VPIphotonics. More information about LaserMatrix below.

Target audience(s): The tutorial is addressed to undergraduate and postgraduate University students in Physics, Photonics, and optical communications as well as young engineers and professionals involved in semiconductor laser design.

Pre-required knowledge: Basics about semiconductor lasers and modulation methods, including concepts like carriers, photons, conduction band, valence band, bandgap, quantum wells, chirp, modulation response, eye diagram, OOK, PAM4, PAM6.


  • Design considerations for conventional and cavity enhanced high speed DMLs
  • The three bandwidth limits: thermal, damping and parasitic
  • High speed characterization methods
  • State-of-the-art high speed DML results
  • Introduction to the LaserMatrix program

About LaserMatrix: LaserMatrix is a powerful user-friendly CAD-tool for designing the longitudinal cavity of complex semiconductor lasers, primarily edge emitter lasers. It is widely used by industry and academia and takes into account spatial hole burning, gain compression and the thermal dependence of material parameters. The modally resolved dynamic model can be used to study large signal characteristics (e.g. turn-on transients and eye diagrams), small signal characteristics (e.g. modulation response and chirp), and noise characteristics (RIN, frequency noise, linewidth and optical spectrum). Please contact if you are interested in a free evaluation version.

Sponsored by: EU H2020 ICT project TWILIGHT

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Free Upcoming WEBINAR series – PART I
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