Generating free-space structured light with programmable integrated photonics

TL;DR

This paper demonstrates a programmable integrated photonic system capable of generating and controlling complex free-space structured light beams rapidly and efficiently, advancing the capabilities of beam shaping technologies beyond traditional liquid-crystal devices.

Contribution

It introduces a novel on-chip method for reconfigurable, lossless control of structured light, combining integrated photonics with free-space beam shaping.

Findings

Achieved microsecond switching times for beam reconfiguration.

Demonstrated lossless, programmable control of amplitude and phase.

Enabled generation of higher-order structured light beams.

Abstract

Structured light is a key component of many modern applications, ranging from superresolution microscopy to imaging, sensing, and quantum information processing. As the utilization of these powerful tools continues to spread, the demand for technologies that enable the spatial manipulation of fundamental properties of light, such as amplitude, phase, and polarization grows further. In this respect, technologies based on liquid-crystal cells, e.g., spatial light modulators, became very popular in the last decade. However, the rapidly advancing field of integrated photonics allows entirely new routes towards beam shaping that not only outperform liquid-crystal devices in terms of speed, but also have substantial potential with respect to robustness and conversion efficiencies. In this study, we demonstrate how a programmable integrated photonic processor can generate and control higher-order free-space structured light beams at the click of a button. Our system offers lossless and reconfigurable control of the spatial distribution of light's amplitude and phase, with switching times in the microsecond domain. The showcased on-chip generation of spatially tailored light enables an even more diverse set of methods, applications, and devices that utilize structured light by providing a pathway towards combining the strengths of programmable integrated photonics and free-space structured light.