Design of an ultra-compact low-crosstalk sinusoidal silicon waveguide array for optical phased array.

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Nanophotonics

Background:

• Optical phased arrays (OPAs) are crucial for beam steering but face challenges with power consumption and field of view.
• Minimizing crosstalk and maintaining a small pitch in silicon waveguide arrays are key to improving OPA performance.
• Existing designs often struggle to balance compactness with low crosstalk, limiting OPA efficiency.

Purpose of the Study:

• To propose and analyze an ultra-compact, low-crosstalk sinusoidal silicon waveguide array.
• To demonstrate the effectiveness of sinusoidal bends in reducing inter-waveguide crosstalk.
• To provide a design enabling energy-efficient OPAs with a large field of view.

Main Methods:

• Designing individual low-crosstalk sinusoidal silicon waveguides with a 695 nm pitch.
• Developing a waveguide array based on the sinusoidal waveguide design.
• Simulating array performance, including insertion loss and crosstalk at 1550 nm.
• Analyzing fabrication error tolerance and optimizing waveguide spacing.

Main Results:

• Achieved an insertion loss of 0.08 dB and crosstalk below -26 dB for a 100 µm array length at 1550 nm.
• Demonstrated favorable fabrication error tolerance for the 695 nm pitch array.
• Showcased the possibility of reducing the center-to-center distance to 615 nm while maintaining acceptable crosstalk.

Conclusions:

• The sinusoidal silicon waveguide array design effectively reduces crosstalk and allows for a smaller pitch.
• This compact, low-crosstalk array is suitable for energy-efficient optical phased arrays with enhanced beam-steering capabilities.
• The design offers a pathway to OPAs with improved power efficiency and a larger field of view.