Fabrication of an integrated optical filter using a large-core multimode waveguide vertically coupled to a...

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Integrated Optics

Background:

• Vertical integration of single-mode and multimode waveguides is challenging.
• Efficient optical signal dropping requires precise fabrication and material selection.

Purpose of the Study:

• To demonstrate a fabrication process for vertically aligned single-mode and multimode waveguides.
• To propose and realize a long-period grating filter for wavelength-specific optical signal dropping.

Main Methods:

• Utilized perfluorocyclobutane and benzocyclobutane for single-mode waveguide fabrication.
• Employed Norland Optical Adhesive 61 for the large-core multimode waveguide.
• Fabricated a long-period grating for wavelength filtering.

Main Results:

• Successfully fabricated vertically aligned single-mode and multimode waveguides on a single substrate.
• Demonstrated an optical filter with a center wavelength of 1537.7 nm.
• Achieved a maximum attenuation of 17.8 dB at the center wavelength for a grating period of 315.9 µm.

Conclusions:

• The demonstrated fabrication process is feasible for integrated optical devices.
• The proposed long-period grating filter effectively drops optical signals in a specific wavelength band.
• This technology holds potential for advanced optical communication and signal processing applications.