Fig. 3: Brillouin laser with a sub-mW threshold power using a high-Q resonator.
From: Universal light-guiding geometry for on-chip resonators having extremely high Q-factor
a Optical spectra obtained by an optical spectrum analyzer with pump powers below threshold (blue line) and above threshold (red line). The Brillouin shift of 7.74 GHz was measured by an electrical spectrum analyzer. b Input pump power versus Brillouin lasing power. A lasing threshold power of 0.53 mW is obtained by a linear fitting of the data (gray line).
