Effective half-wavelength pitch optical phased array design for aliasing-free 2D beam steering

Area of Science:

• Photonics
• Antenna Engineering
• Optical Engineering

Background:

• Optical phased arrays (OPAs) are crucial for beam steering applications.
• Traditional OPA designs require antennas spaced at half-wavelength intervals, limiting practical implementation.
• Achieving both narrow beam width and wide-angle steering simultaneously is a significant challenge.

Purpose of the Study:

• To propose a new OPA design methodology.
• To enable aliasing-free 2D beam steering with narrow beam width.
• To overcome the limitations of half-wavelength antenna spacing.

Main Methods:

• A novel antenna arrangement using location projection to create an effective half-wavelength pitch in one direction.
• Utilizing large antenna spacing in the orthogonal direction to form an effective large aperture.
• Theoretical analysis and numerical simulations to validate the design.

Main Results:

• The proposed method achieves an effective grating-lobe-free far field comparable to conventional half-wavelength pitch designs.
• Demonstrated 180° steering capability.
• Achieved a minimal beam width of 0.4° x 0.032° with >13 dB sidelobe suppression.

Conclusions:

• The presented OPA design method successfully achieves narrow beam width and aliasing-free 2D beam steering.
• This approach offers a practical alternative to traditional OPA designs by relaxing the half-wavelength spacing constraint.
• The design holds promise for advanced optical systems requiring precise and efficient beam control.