fs pulse generation with MIXSEL (mode-locked integrated external cavity surface emitting laser) based on quantum dot amplifying and absorbing elements (QD-MIXSEL)

• Applicant: Professor Dr. Johann Peter Reithmaier
• Subject Area: Experimental Condensed Matter Physics ; Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 286077633

The group aims to realize first compact semiconductor based high-power fs laser sources for frequency comb generation, which will be well beyond the current state-of-the art and which are suitable for coherent communication systems. The joint project combines the expertise of three leading groups, i.e. (i) the group of Ursula Keller (ETH Zürich) who is a leader in the development of ultra-short pulsed high power vertical external cavity surface emitting lasers (VECSELs) development (Keller's group), (ii) the group of Johann Peter Reithmaier (INA, University of Kassel) who is a leader in GaAs based high-power quantum dot (QD) laser material, and (iii) the group of Gadi Eisenstein (Technion, Israel) who is expert and leader in dynamic characterization of QD lasers and device simulation. To achieve this goal, a quantum dot mode locked integrated external cavity surface emitting laser (QD-MIXSEL) will be realized consisting of a QD-VECSEL structure with a QD gain region monolithically integrated with a QD semiconductor saturable absorbing mirror (QD-SESAM). The major objectives are to- develop an optimized QD gain section in VECSELs and MIXSELs for high-power sub-picosecond pulse generation around 950 nm center wavelength- develop optimized QD saturable absorber parameters with low saturation fluence and fast recovery time taking into account annealing during the full MIXSEL growth- demonstrate high average power (> 1 W) femtosecond (< 500 fs) pulse duration from a SESAM modelocked VECSEL using the optimized QD parameters for gain and absorber- demonstrate high average power (> 1 W) femtosecond (< 500 fs) pulse duration from a MIXSEL using the optimized QD parameters for gain and integrated absorber- demonstrate stable frequency comb generation using the SESAM modelocked VECSEL or directly the MIXSELAll of the aimed parameters are well beyond state-of the art and would mark a breakthrough in the understanding of optimizing QD-MIXSELs as well as for using comb generating MIXSELs for coherent communication systems, which was up to now not possible due to the limited output power and/or limited bandwidth caused by the minimal pulse length of existing devices.

• DFG Programme: Research Grants
• International Connection: Israel, Switzerland
• Partner Organisation: Schweizerischer Nationalfonds (SNF)
• Cooperation Partner: Professorin Dr. Ursula Keller
• International Co-Applicant: Professor Dr. Gadi Eisenstein