Department of Electrical and Electronics Engineering2024-11-0920191094-408710.1364/OE.27.0035422-s2.0-85060980318https://hdl.handle.net/20.500.14288/3301We present a CMOS-compatible. Q-switched mode-locked integrated laser operating at 1.9 mu m with a compact footprint of 23.6 x 0.6 x 0.78mm. The Q-switching rate is 720 kHz, the mode-locking rate is 1.2 GHz, and the optical bandwidth is 17nm, which is sufficient to support pulses as short as 215 fs. The laser is fabricated using a silicon nitride on silicon dioxide 300-mm wafer platform, with thulium-doped Al2O3 glass as a gain material deposited over the silicon photonics chip. An integrated Kerr-nonlinearity-based artificial saturable absorber is implemented in silicon nitride. A broadband (over 100 nm) dispersion-compensating grating in silicon nitride provides sufficient anomalous dispersion to compensate for the normal dispersion of the other laser components, enabling femtosecond-level pulses. The laser has no off-chip components with the exception of the optical pump, allowing for easy co-integration of numerous other photonic devices such as supercontinuum generation and frequency doublers which together potentially enable fully on-chip frequency comb generation.pdfOpticsIntegrated CMOS-compatible Q-switched mode-locked lasers at 1900nm with an on-chip artificial saturable absorberJournal Articlehttps://doi.org/10.1364/OE.27.003542457585600149Q2NOIR01705