Passive wavelength selective polarization rotator in a hybrid waveguide platform

Area of Science:

• Photonics
• Integrated Optics
• Materials Science

Background:

• Polarization rotation and wavelength filtering are essential for photonic integrated circuits.
• Existing methods often require active components or are limited in functionality.
• Silicon nitride and amorphous silicon offer promising material properties for integrated photonics.

Purpose of the Study:

• To propose and demonstrate a novel, fully passive wavelength-selective polarization rotator-cum-filter.
• To explore simultaneous coarse wavelength division multiplexing and polarization rotation in a passive configuration.
• To investigate the bandwidth engineering capabilities of the proposed hybrid waveguide.

Main Methods:

• Fabrication of a silicon nitride/amorphous silicon hybrid waveguide.
• Experimental demonstration of TE0 → TM0 and TM0 → TE0 polarization rotation.
• Characterization of wavelength selectivity and 3dB bandwidth.
• Proof-of-concept demonstration of simultaneous wavelength division multiplexing and polarization rotation.

Main Results:

• Achieved wavelength-selective polarization rotation with a measured 3dB bandwidth of 14.8 nm.
• Demonstrated simultaneous coarse wavelength division multiplexing and polarization rotation in a passive configuration for the first time.
• Showcased bandwidth engineering feasibility, ranging from 0.59 nm to 81 nm.

Conclusions:

• The proposed hybrid waveguide offers a unique solution for integrated photonic circuits requiring both wavelength selectivity and polarization control.
• This passive approach simplifies device design and potentially reduces power consumption.
• The demonstrated flexibility in bandwidth engineering opens new avenues for advanced photonic device applications.