Brillouin backaction thermometry for modal temperature control
Stimulated Brillouin scattering provides optical gain for efficient and narrow-linewidth lasers in high-Q microresonator systems. However, the thermal dependence of the Brillouin process as well as the microresonator frequencies impose strict temperature control requirements for long term frequency-stable operation. Here, we study Brillouin backaction and use it to both measure and phase-sensitively lock modal temperature to a reference temperature defined by the Brillouin phase matching condition. At a specific lasing wavelength, the reference temperature can be precisely set by adjusting the resonator's free spectral range. This backaction control method is demonstrated in a chip-based Brillouin laser, but can be applied in all Brillouin laser platforms. It offers a new approach for frequency-stable operation of Brillouin lasers in atomic clock, frequency metrology, and gyroscope applications.
Additional Information© 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement. Received 21 March 2022; revised 31 May 2022; accepted 1 June 2022; published 24 June 2022. Yu-Kun Lu thanks the Caltech SURF program for financial support. Funding: Defense Advanced Research Projects Agency (N66001-16-1-4046); Air Force Office of Scientific Research (FA9550-18-1-0353); Kavli Nanoscience Institute. The authors declare no conflicts of interest. Data availability: Data underlying the results presented in this paper are not publicly available at this time but may be obtained from the authors upon reasonable request.
Published - optica-9-7-701.pdf
Submitted - 2205.07181.pdf
Supplemental Material - 5878941.pdf