Narrowband multichannel filters and integrated optical filter arrays

Area of Science:

• Photonics
• Optical Engineering
• Materials Science

Background:

• Multichannel optical filters are crucial for various applications, demanding precise control over spectral selectivity.
• Existing filter technologies often face limitations in achieving simultaneous narrowband and multichannel performance.

Purpose of the Study:

• To propose and demonstrate three distinct approaches for fabricating narrowband multichannel filters.
• To investigate the filtering characteristics and potential applications of these novel filter designs.

Main Methods:

• Fabrication and characterization of multiple heterostructures with defects for multichannel filtering.
• Design and analysis of guided-mode resonance (GMR) Brewster filters using single-layer and double-layer gratings.
• Development of a combinatorial etching technique for creating integrated narrow bandpass filter arrays.

Main Results:

• Demonstrated simultaneous enlargement of the forbidden band and multichannel filtering in heterostructures with defects.
• Achieved multichannel GMR Brewster filters using single-layer gratings and homogeneous/grating double-layer structures.
• Successfully fabricated integrated narrow bandpass filter arrays with 32 elements using a combinatorial etching technique.

Conclusions:

• The proposed methods effectively achieve narrowband multichannel filtering with good performance.
• These filters are suitable for a wide range of optical applications requiring precise spectral control.
• The developed combinatorial etching technique offers a scalable approach for fabricating advanced optical filters.