Spin separation based on-chip optical polarimeter via inverse design.

Area of Science:

• Nanophotonics
• Optical Engineering
• Integrated Photonics

Background:

• Polarimetry is vital across optics, imaging, and astronomy.
• On-chip nanostructures offer miniaturization potential for polarimeters, replacing bulk optics.
• Existing on-chip polarimeters face challenges like low coupling efficiency and circuit complexity.

Purpose of the Study:

• To introduce and investigate a novel on-chip polarimeter utilizing nanostructures and inverse design.
• To demonstrate the device's capability in detecting both spin and linear polarization states.
• To validate the device for high-speed Stokes vector optical signal detection.

Main Methods:

• Utilized inverse design methodology for nanostructure development.
• Integrated nanophotonic structures for on-chip polarization detection.
• Experimental validation of Stokes parameter retrieval and high-speed communication performance.

Main Results:

• The developed on-chip polarimeter successfully detects four polarization components (two spin, two linear).
• Experimental Stokes parameter retrieval closely matches numerical simulations.
• Demonstrated proof-of-concept for high-speed Stokes vector detection up to 16 GBd with a low bit error rate.

Conclusions:

• The proposed nanostructure-based on-chip polarimeter offers a compact and efficient solution.
• The device shows significant promise for Stokes polarimetry and high-speed optical communication systems.
• This work advances the integration of polarimetry functionalities onto photonic chips.