A reconfigurable multi-channel on-chip photonic filter for programmable optical frequency division

Area of Science:

• Photonics
• Optical Communications
• Integrated Optics

Background:

• Bragg gratings are crucial for photon filters in optical networks.
• Traditional gratings have fixed refractive index modulation, limiting flexibility.
• Reconfigurable filters are needed for adaptable optical communication systems.

Purpose of the Study:

• To introduce a reconfigurable multi-channel photon filter.
• To enable programmable control over transmission spectral features.
• To demonstrate the filter's adaptability for optical communication applications.

Main Methods:

• Utilized a silicon nitride on insulator platform.
• Incorporated a linearly chirped four-phase-shifted sampled Bragg grating.
• Employed micro-heaters for thermo-optic tuning and programmable control.

Main Results:

• Achieved seamless transitions between single, dual, and quad-band configurations, plus band-stop mode.
• Demonstrated independent tuning of each band and precise single-wavelength selection.
• Verified tunability through optical frequency division multiplexing experiments with 50 GHz spacing.

Conclusions:

• The developed filter offers high tunability, low insertion loss, and excellent side-mode suppression.
• This structure supports the integration of programmable photonic devices.
• Enables advancements in space optical communications, photonic integrated networks, and elastic optical networks.