Coupler-apodized Bragg-grating add-drop filter.

Area of Science:

• Photonics
• Integrated Optics
• Nanotechnology

Background:

• Grating-assisted asymmetric couplers are key components in photonic integrated circuits.
• Traditional apodization methods often require complex waveguide structures, limiting fabrication tolerance.
• Efficient sidelobe suppression is crucial for high-performance optical devices.

Purpose of the Study:

• To demonstrate a novel apodization technique for grating-assisted asymmetric couplers.
• To improve fabrication tolerance and simplify the design of photonic devices.
• To achieve high sidelobe suppression ratios using a CMOS-compatible process.

Main Methods:

• Utilizing tapered coupler gaps for apodization in grating-assisted asymmetric couplers.
• Implementing the technique on a submicrometer silicon-on-insulator (SOI) platform.
• Employing a 193 nm lithography process compatible with CMOS fabrication.

Main Results:

• Achieved a high sidelobe suppression ratio of 30 dB.
• Demonstrated an apodization technique that circumvents the need for tapered waveguide perturbations.
• Showcased higher tolerance to fabrication errors compared to conventional methods.

Conclusions:

• The proposed apodization technique using tapered coupler gaps is effective for photonic devices.
• This method offers a practical solution for achieving high sidelobe suppression with improved fabrication tolerance.
• The technique is suitable for mass production using established CMOS-compatible photonics processes.