An all-optical spatial light modulator for field-programmable silicon photonic circuits

TL;DR

This paper introduces an all-optical spatial light modulator in silicon photonics that enables dynamic, field-programmable control of light routing by modifying the device’s refractive index with laser excitation, enhancing reconfigurability.

Contribution

It demonstrates a novel all-optical wavefront shaping method in integrated silicon photonic devices for the first time, allowing external control of optical functionalities.

Findings

Achieved over 97% efficiency in light routing between ports.

Demonstrated full control over the optical transfer function.

Enabled reconfigurable photonic circuit functionalities.

Abstract

Reconfigurable photonic devices capable of routing the flow of light enable flexible integrated-optic circuits that are not hard-wired but can be externally controlled. Analogous to free-space spatial light modulators, we demonstrate all-optical wavefront shaping in integrated silicon-on-insulator photonic devices by modifying the spatial refractive index profile of the device employing ultraviolet pulsed laser excitation. Applying appropriate excitation patterns grants us full control over the optical transfer function of telecommunication-wavelength light travelling through the device, thus allowing us to redefine its functionalities. As a proof-of-concept, we experimentally demonstrate routing of light between the ports of a multimode interference power splitter with more than 97% total efficiency and negligible losses. Wavefront shaping in integrated photonic circuits provides a conceptually new approach toward achieving highly adaptable and field-programmable photonic circuits with applications in optical testing and data communication.