Optomechanical Anti-Lasing with Infinite Group Delay at a Phase Singularity

Abstract

Singularities which symbolize abrupt changes and exhibit extraordinary behavior are of a broad interest. We experimentally study optomechanically induced singularities in a compound system consisting of a three-dimensional aluminum superconducting cavity and a metalized high-coherence silicon nitride membrane resonator. Mechanically induced coherent perfect absorption and anti-lasing occur simultaneously under a critical optomechanical coupling strength. Meanwhile, the phase around the cavity resonance undergoes an abrupt π-phase transition, which further flips the phase slope in the frequency dependence. The observed infinite discontinuity in the phase slope defines a singularity, at which the group velocity is dramatically changed. Around the singularity, an abrupt transition from an infinite group advance to delay is demonstrated by measuring a Gaussian-shaped waveform propagating. Our experiment may broaden the scope of realizing extremely long group delays by taking advantage of singularities.

Application perspective of cavity optomechanical system

“…For the system consisting of a passive optical cavity and an active mechanical resonator, it is shown that the optical amplification and absorption, optomechanically induced transparency and ultralong group delay can be controlled by tuning the gain and loss . The optomechanically induced anti-laser and phase singular transition has been observed experimentally in a compound system composed of a three-dimensional superconducting cavity and a silicon nitride membrane resonator (Liu et al, 2021a). The phenomenon of infinite group delay paves the way for quantum memories.…”

Long-lived Quantum State Storage Based on Coherent Mechanical Excitations

“…Finally, the metallized SiN film will form a mechanical parallel-plate capacitor with the bottom rattlesnake microwave coupler. Compared with the traditional process of first metallizing the front side of the silicon nitride film and then flip-chip packaging [57][58][59][60][61][62][63][64], the dielectric of the mechanical capacitor in this work additionally contains silicon nitride, and the cleanliness of the front side of the film is better guaranteed. Therefore, the vacuum gap (mechanical capacitance) can be as small (large) as possible, to improve the optical force coupling strength.…”

“…Meanwhile, silicon nitride (SiN) membrane resonators have been optomechanically coupled to optical [46][47][48][49][50][51][52][53][54][55][56] or microwave cavities [57][58][59][60][61][62][63][64][65][66][67]. Rational exploitation of the spatial distribution of mechanical modes enables simultaneous coupling of the SiN membrane resonator to both superconducting microwave and optical cavity resonators [68,69].…”

“…Based on microwave field backaction, millimeter-sized SiN membrane resonators have reached their ground-state [61][62][63]. Siliconnitride (SiN) membranes with high stress have a mechanical mode quality factor (Q) in excess of 10 7 , measured in the cryostat [57][58][59][60][61]. On the other hand, by incorporating phononic bandgap engineering with a SiN membrane [63], the Q-value of the mechanical modes can be further improved in excess of 10 9 .…”

Non‐Hermitian Control of Topological Scattering Singularities Emerging from Bound States in the Continuum

“…[52] Moreover, the general wave nature of these phenomena enables them in different wave systems, such as elastic [53] and optomechanical systems. [54] Their ubiquity and importance has especially been proven in disordered electromagnetic systems, [55][56][57] which can be reconfigured and offer more flexibility and precision in designing sensitive singularity-based devices. Although the scattering singularity-based research has considerably proliferated in recent years, their topological features were seldomly discussed and have not been fully assessed.…”