Tunable, oblique incidence resonant grating filter for telecommunications

Area of Science:

• Photonics and optical engineering
• Nanophotonics
• Integrated optics

Background:

• Resonant grating filters (RGFs) are crucial optical components.
• Tunability and miniaturization are key challenges in RGF development.
• C-band applications require precise wavelength control.

Purpose of the Study:

• To design and demonstrate a tunable RGF for C-band applications.
• To investigate the tuning mechanism via an oblique-incidence configuration.
• To analyze the impact of device and beam size on filter performance.

Main Methods:

• Designed an oblique-incidence resonant grating filter.
• Employed a microelectromechanical systems (MEMS) platform for filter tilting.
• Investigated fabrication tolerances, finite incident-beam size, and device size effects.
• Derived efficiency limits and scaling laws for finite-area devices.

Main Results:

• Demonstrated a tunable RGF covering the C-band for TE-polarized light.
• Achieved a linear shift in resonance peak wavelength with angle of incidence.
• Observed minimal change in resonance peak shape (0.4 nm FWHM) across the tuning range.
• Validated simulation results with experimental measurements.

Conclusions:

• The designed MEMS-tuned RGF offers a viable solution for tunable optical filtering.
• The study provides insights into performance limitations and scaling for finite-area RGFs.
• This technology has potential applications in optical communications and sensing.