Tunable optical amplification and group delay in cavity magnomechanics

TL;DR

This paper theoretically explores how to control optical transmission and group delay in a hybrid cavity magnomechanics system with gain and loss components, revealing tunable transparency, amplification, and phase transitions for advanced light manipulation.

Contribution

It introduces a novel hybrid cavity magnomechanics setup with active and passive cavities, enabling tunable transparency, amplification, and phase control in light propagation.

Findings

Observation of magnomechanically induced transparency.

Asymmetric modulation of absorption dips into amplification or absorption.

Control of group delay from positive to negative values.

Abstract

In this work, we theoretically investigate the controllable output probe transmission and group delay in a hybrid cavity magnomechanics (CMM) system. The setup comprises a gain (active) cavity and a passive (loss) cavity, which incorporates an optical parametric amplifier (OPA) and two yttrium iron garnet spheres to facilitate magnon-photon coupling. Unlike the single transparency window typically resulting from magnon-photon interactions, we also observe magnomechanically induced transparency due to nonlinear magnon-phonon interactions. Additionally, two absorption dips on either side of the central absorption dip can be asymmetrically modulated into amplification and absorption by varying different system parameters. A PT-symmetric to broken-PT-symmetric phase transition is observed in both balanced and unbalanced gain-to-loss scenarios. Notably, replacing the second passive cavity with an active one mitigates high absorption and introduces effective gain into the system. Our findings reveal that the group delay of the probe light can be adjusted between positive and negative values by modifying various system parameters. This study provides a robust platform for controlling light propagation in CMM systems, highlighting potential applications in optical communication and signal processing.