Performance estimation of photonic integrated wavefront corrector for single-mode fiber coupling

TL;DR

This paper evaluates a silicon photonics-based wavefront corrector designed to improve single-mode fiber coupling in astronomical telescopes, analyzing factors affecting its performance such as pupil obscuration, tip/tilt correction, and scintillation.

Contribution

It introduces an integrated photonic wavefront corrector for astronomical applications and analyzes external factors influencing its effectiveness.

Findings

Pupil obscuration affects coupling efficiency.

Tip/tilt pre-correction may be necessary.

Scintillation impacts correction quality.

Abstract

Many modern astronomical instruments rely on the optimal coupling of starlight into single-mode fibers (SMFs). For ground-based telescopes, this coupling is limited by atmospheric turbulence. We propose an integrated wavefront corrector based on silicon-on-insulator (SOI) photonics, which samples the aberrated wavefront via a microlens array (MLA). The MLA focuses the sampled wavefront onto an array of grating couplers that inject the beamlets into the single-mode waveguides of the corrector. The beams in each waveguide are then shifted in phase using thermo-optic phase shifters before combining the co-phased beams into one single-mode waveguide. In this work, we analyze the external factors that we anticipate will impact the performance of the corrector. Specifically, we study the effects of the telescope pupil function with obscuration, determine whether the corrector requires tip/tilt pre-correction, and analyze the impact of scintillation on the correction quality.