Optical spring limitations in phonon lasing

Abstract

This report provides a comprehensive review of optomechanical systems and cavity physics, with a focus on the effects of the optical spring effect, particularly in multimode phonon lasing. In contrast with single-mode coupling in traditional optomechanical cavities, this research explores how the optical spring effect has a comparatively smaller impact in systems with multiple mechanical modes. This is especially relevant when these systems achieve a mode-locked state through techniques like Floquet dynamics. Experimental and theoretical investigations suggest that multimode phonon lasing can lead to significantly improved long-term frequency stability when compared to single-mode operation. This analysis delves into the conditions under which the frequency shifts induced by the optical spring effect remain smaller than the mechanical linewidths, specifically considering three modes in the multimode system, ensuring robust mode locking and stable operation. This work paves the way for future exploration into increasing the mode count for multimode systems to potentially achieve even stronger effects and enhance the functionalities of these systems.