# Direction reconfigurable non-reciprocal acousto-optic modulator on chip

## TL;DR

This paper presents a dynamically reconfigurable on-chip non-reciprocal acousto-optic modulator that uses a novel transducer design to control signal directionality, promising advanced optical isolation and signal processing capabilities.

## Contribution

It introduces a new reconfigurable acousto-optic modulator with a cross-finger transducer enabling dynamic control of non-reciprocity at telecom wavelengths.

## Key findings

- Demonstrated dynamic reconfigurability of the modulator.
- Achieved multiple reciprocal and non-reciprocal configurations.
- Enabled phase-controlled directionality of acoustic excitation.

## Abstract

Non-reciprocal components are essential in photonic systems for protecting light sources and for signal routing functions. Acousto-optic methods to produce non-reciprocal devices offer a foundry-compatible alternative to magneto-optic solutions and are especially important for photonic integration. In this paper, we experimentally demonstrate a dynamically reconfigurable non-reciprocal acousto-optic modulator at telecom wavelength. The modulator can be arranged in a multitude of reciprocal and non-reciprocal configurations by means of an external RF input. The dynamic reconfigurability of the device is enabled by a new cross-finger interdigitated piezoelectric transducer that can change the directionality of the reciprocity-breaking acoustic excitation based on the phase of the RF input. The methodology we demonstrate here may enable new avenues for direction dependent signal processing and optical isolation.