Shtyrkova Katia, Callahan Patrick T, Li Nanxi, Magden Emir Salih, Ruocco Alfonso, Vermeulen Diedrik, Kärtner Franz X, Watts Michael R, Ippen Erich P
Opt Express. 2019 Feb 4;27(3):3542-3556. doi: 10.1364/OE.27.003542.
We present a CMOS-compatible, Q-switched mode-locked integrated laser operating at 1.9 µm with a compact footprint of 23.6 × 0.6 × 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 AlO 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.
我们展示了一种与CMOS兼容的调Q锁模集成激光器，工作波长为1.9 µm，紧凑尺寸为23.6×0.6×0.78mm。调Q速率为720 kHz，锁模速率为1.2 GHz，光学带宽为17nm，足以支持短至215 fs的脉冲。该激光器采用二氧化硅上的氮化硅300毫米晶圆平台制造，以掺铥的AlO玻璃作为增益材料沉积在硅光子芯片上。在氮化硅中实现了基于集成克尔非线性的人工可饱和吸收体。氮化硅中的宽带（超过100 nm）色散补偿光栅提供了足够的反常色散，以补偿其他激光组件的正常色散，从而实现飞秒级脉冲。除了光泵浦外，该激光器没有片外组件，这使得它能够轻松地与许多其他光子器件（如超连续谱产生和倍频器）共同集成，这些器件一起有可能实现全片上频率梳的产生。
