Fast beam steering with full polarization control using a galvanometric optical scanner and polarization controller

TL;DR

This paper presents a fast, integrated system combining a galvanometric scanner and polarization controller that enables precise polarization control during beam steering, suitable for various industrial and scientific applications.

Contribution

The development of a polarization steerable system with feed-forward control that maintains polarization state during rapid beam steering is novel.

Findings

Can compensate polarization errors larger than 0.2 rad within 20 ms

Enables polarization control without affecting beam pointing direction

System is potentially integrable and robust

Abstract

Optical beam steering is a key element in many industrial and scientific applications like in material processing, information technologies, medical imaging and laser display. Even though galvanometer-based scanners offer flexibility, speed and accuracy at a relatively low cost, they still lack the necessary control over the polarization required for certain applications. We report on the development of a polarization steerable system assembled with a fiber polarization controller and a galvanometric scanner, both controlled by a digital signal processor board. The system implements control of the polarization decoupled from the pointing direction through a feed-forward control scheme. This enables to direct optical beams to a desired direction without affecting its initial polarization state. When considering the full working field of view, we are able to compensate polarization angle errors larger than 0.2 rad, in a temporal window of less than $\sim 20$ ms. Given the unification of components to fully control any polarization state while steering an optical beam, the proposed system is potentially integrable and robust.