Integrated fiber-PIC synthetic aperture chip enables 2D high-resolution interferometric imaging

Area of Science:

• Optics and Photonics
• Interferometry
• Integrated Circuit Technology

Background:

• Synthetic aperture interferometry (SAI) is crucial for high-resolution imaging but limited by fixed baselines (<20 mm) and sampling aliasing.
• Current systems struggle with baseline reconfigurability and artifacts in 2D image reconstruction.

Purpose of the Study:

• To develop an adaptive baseline SAI system overcoming current limitations.
• To enhance imaging resolution and flexibility for space optics and precision metrology applications.

Main Methods:

• A hybrid fiber-PIC architecture with dynamically tunable fiber delay lines for continuous baseline adjustment (10-50 mm).
• A wheel-optimized non-uniform radial sampling strategy to minimize spectral matrix mapping errors.
• Prioritizing baseline angles intersecting frequency grid points for improved sampling.

Main Results:

• Achieved a 1.6 dB PSNR improvement and 4.3 RMSE reduction for structured targets compared to uniform sampling.
• Demonstrated superior fringe clarity and accurate fringe count resolution matching target spatial frequencies.
• Successfully reconstructed 2D features of a 5 lp/mm target across multiple angular configurations (0°-150°).

Conclusions:

• The developed system establishes a new paradigm for adaptive baseline synthetic aperture imaging.
• Paves the way for deployable interferometric imagers in mass/volume-critical scenarios like CubeSats and endoscopic sensing.