Experimental demonstration of interferometric imaging using photonic integrated circuits

Area of Science:

• Photonics
• Optical Engineering
• Integrated Optics

Background:

• Interferometric imaging requires precise optical path control.
• Photonic integrated circuits (PICs) offer miniaturization and stability for optical systems.

Purpose of the Study:

• To design, fabricate, and demonstrate a silica PIC for interferometric imaging.
• To perform complex visibility measurements using multiple baselines.
• To validate the PIC's performance with point sources and extended objects.

Main Methods:

• Fabrication of a silica PIC with twenty waveguides leading to sixty three-band spectrometers.
• Integration of tunable Mach-Zehnder interferometers (MZIs) for interferogram construction.
• Experimental setup utilizing two baselines for visibility measurements at 1550 nm.

Main Results:

• Demonstrated near-unity instrumental visibility using a point source.
• Successfully measured visibility for a variable width slit (0-500 µm) across 5 and 20 mm baselines.
• Experimental results showed good agreement with theoretical predictions.

Conclusions:

• The developed silica PIC is effective for interferometric imaging and visibility measurements.
• The PIC demonstrates high accuracy for both point-like and extended sources.
• This technology has potential applications in optical metrology and imaging.