Subwavelength structure engineered passband filter for the 2-µm wave band

Area of Science:

• Photonics and Optical Engineering
• Materials Science

Background:

• Integrated photonics enables compact optical devices.
• Silicon-on-insulator (SOI) is a key platform for photonic integrated circuits.
• Filters are crucial components in optical communication systems.

Purpose of the Study:

• To experimentally demonstrate a novel passband filter for the 2-µm wave band.
• To achieve high performance metrics including bandwidth, sidelobe suppression, and insertion loss.
• To utilize the silicon-on-insulator platform for integrated photonic applications.

Main Methods:

• Fabrication of a device on a 340-nm-thick silicon membrane.
• Integration of a strip waveguide with an apodized subwavelength-structured waveguide.
• Experimental characterization of the passband filter's optical performance.

Main Results:

• Demonstration of a passband filter operating in the 2-µm wave band.
• Achieved a 3-dB bandwidth of 16-33 nm.
• Obtained a high sidelobe suppression ratio (SLSR) of 24 dB.
• Measured a low insertion loss (IL) of 0.4 dB.

Conclusions:

• The proposed SOI passband filter is a high-performance component for the 2-µm wave band.
• The device design and fabrication are suitable for integrated photonic applications.
• The demonstrated filter offers a promising solution for optical communication and sensing systems.