Inverse-designed polarization multiplexing non-uniformly distributed gratings for one-dimensional beam steering

Area of Science:

• Photonics and Optical Engineering
• Nanotechnology
• Integrated Optics

Background:

• Silicon-on-insulator (SOI) platform is a key material for integrated photonics.
• Beam steering is crucial for optical communication and sensing systems.
• Current beam steering technologies often lack sufficient scanning angles or miniaturization.

Purpose of the Study:

• To design and demonstrate non-uniformly distributed gratings for enhanced one-dimensional beam steering.
• To investigate the performance of these gratings in terms of scanning angle and efficiency.
• To explore the potential for miniaturized optical phased arrays.

Main Methods:

• Utilizing a direct binary search inverse-design method for grating optimization.
• Simulating and analyzing the far-field characteristics and emission directionality.
• Optimizing grating parameters including polarization multiplexing and etching depth.

Main Results:

• Non-uniform gratings exhibit superior emission directionality and far-field properties.
• Achieved longitudinal scanning angles of 23.65° (TE) and 10.81° (TM) over a 60 nm wavelength range.
• Demonstrated a remarkable 32.10° scanning angle with 0.55°/nm efficiency through optimization.

Conclusions:

• Non-uniform gratings significantly outperform uniform gratings in beam steering capabilities.
• The proposed design offers a pathway to highly efficient, miniaturized optical phased arrays.
• This advancement holds promise for next-generation optical systems requiring precise beam control.