# An optomechanical heat engine with feedback-controlled in-loop light

## TL;DR

This paper demonstrates how feedback-controlled light can enhance an optomechanical heat engine's performance, enabling operation under less restrictive conditions and easing practical implementation.

## Contribution

It introduces a feedback mechanism to improve an optomechanical heat engine, allowing operation in broader parameter regimes and near instability thresholds.

## Key findings

- Feedback control extends operational regimes of the heat engine.
- Positive feedback near instability enhances engine performance.
- Feedback enables practical implementation under less restrictive conditions.

## Abstract

The dissipative properties of an optical cavity can be effectively controlled by placing it in a feedback loop where the light at the cavity output is detected and the corresponding signal is used to modulate the amplitude of a laser field which drives the cavity itself. Here we show that this effect can be exploited to improve the performance of an optomechanical heat engine which makes use of polariton excitations as working fluid. In particular we demonstrate that, by employing a positive feedback close to the instability threshold, it is possible to operate this engine also under parameters regimes which are not usable without feedback, and which may significantly ease the practical implementation of this device.