Ultra-High Q Silicon Nitride Microresonators Enabled Raman Lasing

Silicon nitride (Si3N4), among other materials, is particularly attractive for linear and nonlinear optics because of its ultra-low loss properties, enabling advances in various fields, including narrow linewidth lasers [1], Kerr frequency comb [2], quantum photonics [3], etc. One of the important examples is stimulated Raman scattering. It is an efficient approach to extend the available spectral coverage of conventional laser sources [4], [5], enabling applications including molecular spectroscopy, environmental analysis, and biological detection [6]. Intrapulse Raman scattering is broadband in nature in amorphous materials such as silica and Si3N4, which relates to the vibrational material response of the cubic nonlinearity. This work presents the on-chip continuous-wave (CW) Raman laser generation in Si3N4 platform, which is benefited from the enhanced intracavity power of ultra-high quality factor (Q) microresonators.