Multichannel bandpass filters utilizing multilayer photonic crystal

Area of Science:

• Photonics and optical engineering
• Materials science

Background:

• Dielectric multilayers are crucial for optical filter applications.
• Patterned substrates offer a route to novel optical device functionalities.

Purpose of the Study:

• To demonstrate multichannel optical bandpass filters.
• To investigate the use of patterned substrates for filter fabrication.
• To analyze the control of filter characteristics by substrate design.

Main Methods:

• Fabrication of microstructured Si/SiO(2) multilayers on fused silica substrates with surface gratings using rf biased magnetron sputtering.
• Characterization of filter bandwidths and center wavelengths in the near-infrared region.

Main Results:

• Successful demonstration of multichannel optical bandpass filters.
• Measured filter channel bandwidths ranging from 50 to 175 nm.
• Verification of center wavelength and bandwidth control through grating pitch modification.

Conclusions:

• Alternating dielectric multilayers on patterned substrates enable the creation of multichannel optical filters.
• Grating pitch provides an effective means to tune filter performance.
• This approach offers a pathway for designing tailored optical filtering devices.