A Framework for Closed-Loop Robotic Assembly, Alignment and Self-Recovery of Precision Optical Systems

Abstract

Robotic automation has transformed scientific workflows in domains such as chemistry and materials science, yet free-space optics, which is a high precision domain, remains largely manual. Optical systems impose strict spatial and angular tolerances, and their performance is governed by tightly coupled physical parameters, making generalizable automation particularly challenging. In this work, we present a robotics framework for the autonomous construction, alignment, and maintenance of precision optical systems. Our approach integrates hierarchical computer vision systems, optimization routines, and custom-built tools to achieve this functionality. As a representative demonstration, we perform the fully autonomous construction of a tabletop laser cavity from randomly distributed components. The system performs several tasks such as laser beam centering, spatial alignment of multiple beams, resonator alignment, laser mode selection, and self-recovery from induced misalignment and disturbances. By achieving closed-loop autonomy for highly sensitive optical systems, this work establishes a foundation for autonomous optical experiments for applications across technical domains.

Figures (5)

• Figure 1: A general overview of the (a) challenges associated with automating reconfigurable optics experiments and (b, c) the solutions proposed and implemented in this work.
• Figure 2: High-precision automated optical experiments using (a) spatial optimization and (b) angular optimization. For the camera image in (b), the original image was enhanced following the logarithmic intensity transformation: $I_{\textrm{processed}}= \textrm{log}(1+10I_{\textrm{raw}})/\textrm{log(1+10)}$, where $I_{\textrm{processed}}$ and $I_{\textrm{raw}}$ are normalized intensity of the processed image and the raw image. OC: out-coupler, IC: in-coupler.
• Figure 3: (a) The fundamental architecture of a laser cavity setup and its associated alignment objectives. (b) The spatial and angular precision necessary for the placement of various optical components for this setup. The precision for each component is calculated using the actual components used during the experiment. (c) Pipeline for autonomous construction of the setup. Videos of the steps in two distinct successful trials can be found in the https://anonymous.4open.science/r/AutomateOptics-7C7C/README.md.
• Figure 4: (a) Observed laser power curve showing a clear threshold. (b) Lasing in higher-order cavity modes due to small misalignments. (c) Optimizing the laser mode by utilizing the robotic arm in conjunction with the FAT.
• Figure 5: Self-recovery of the experimental setup in response to $\textbf{(a)}$ component displacement and $\textbf{(b)}$ simulated drift of the mirror adjustment knobs.