Chunnong Zhao

We demonstrate the ability to manipulate the optical spring (OS) effect by integrating an optical parametric amplifier (OPA) into an optical cavity. The resonance profiles of the OPA cavity were measured as the OPA phase was tuned to both amplification and de-amplification modes. Our observation revealed changes in the effective cavity linewidth, a twofold increase in the OS frequency shift, and a fourfold enhancement in the optomechanical damping under OPA amplification.

Abstract The sensitivity of laser interferometers is fundamentally limited by the quantum nature of light. Recent theoretical studies have opened a new avenue to enhance their quantum-limited sensitivity by using active parity-time-symmetric and phase-insensitive quantum amplification. These systems can enhance the signal response without introducing excess noise in the ideal case.

Abstract Parametric instability (PI) is a phenomenon that results from resonant interactions between optical and acoustic modes of a laser cavity. This is problematic in gravitational wave interferometers where the high intracavity power and low mechanical loss mirror suspension systems create an environment where three-mode PI will occur without intervention.