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

该小组的目标是实现第一个基于紧凑型半导体的高功率飞秒激光光源，用于频率梳产生，这将远远超过当前最先进的水平，并适用于相干通信系统。该联合项目汇集了三个领导小组的专门知识，即(I)Ursula Keller(ETH Zürich)小组(以色列理工学院)，他们是超短脉冲高功率垂直外腔表面发射激光器(VECSEL)开发(凯勒小组)的领导者(Keller‘s小组)，(Ii)Johann Peter Reithmaier(卡塞尔大学)，他是基于砷化镓的高功率量子点(QD)激光材料的领导者；(Iii)Gadi Eisenstein(以色列理工学院)，是量子点激光器动态表征和器件模拟方面的专家和领导者。为了实现这一目标，我们将实现一种量子点锁模集成外腔面发射激光器(QD-MIXSEL)，该激光器由具有QD增益区的QD-VECSEL结构和QD半导体可饱和吸收镜(QD-SESAM)单片集成而成。主要目标是-在VECSEL和MIXSEL中开发用于产生约950 nm中心波长的高功率亚皮秒脉冲的优化的量子点增益部分-开发具有低饱和通量和快速恢复时间的优化的量子点可饱和吸收参数，并考虑到在整个MIXSEL生长过程中的退火-展示来自SESAM模型锁定的VECSEL的高平均功率(&gt；1 W)飞秒(&lt；500 fs)脉冲持续时间-展示高平均功率(&gt；1 W)飞秒(&lt；使用用于增益和集成吸收的优化QD参数从MIXSEL获得脉冲持续时间-使用SESAM模型锁定的VECSEL或直接使用MIXSEL产生稳定的频率梳-所有目标参数都远远超出了现有技术的水平，并将标志着对优化QD-MIXSEL以及用于相干通信系统的梳状产生MIXSEL的理解的突破，这到目前为止是不可能的，因为现有设备的最小脉冲长度导致的输出功率和/或带宽有限。

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.