Nonlinear Dynamics in Semiconductor Lasers 2023 - Abstract
Wohlfeil, Shulin
In this talk, we will present experimental and theoretical results of a monolithically integrated double quantum well laser designed for ultrashort pulse generation. This laser shows promise as a potential alternative to Ti:Sapphire lasers in compact Terahertz time-domain spectroscopy systems. The diode laser, measuring 6 mm in length, incorporates three sections, including a gain-guided tapered (TP) gain section, an index-guided ridge waveguide (RW) gain section and an additional RW section that functions as a saturable absorber. Under passive mode-locking operation, the shortest pulses measure around 3 ps in pulse duration (full width at half maximum). At the same time, the measured pulse peak power can reach as high as 40 W, which is the highest peak power achieved from a monolithically integrated mode-locked quantum well diode laser to the best of our knowledge. The corresponding central emitting wavelength is 830 nm. The pulse repetition rate is 6.3 GHz. The generated pulses are not transform-limited and can therefore be compressed resulting in even shorter pulses with more intense peak power. The experimental results will be compared with numerical simulations to gain a deeper insight into the laser dynamics. For the simulations, we employ BALaser, a software tool developed by the Weierstrass Institute Berlin. BALaser is specifically designed for simulating the nonlinear dynamics in high-power edge-emitting semiconductor lasers. This software integrates the 1 2 dimensional traveling wave model, which describes the dynamics of high-power diode lasers taking into account the lateral and longitudinal dimensions. The simulation model also incorporates thermal effect to provide a comprehensive analysis.